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•	a system (including an LNG storage facility) owned by Paiute extending from the Idaho-Nevada border to the Reno, Sparks, and Carson City areas and communities in the Lake Tahoe area in both California and Nevada and other communities in northern and western Nevada; and

•	a system extending from the Colorado River at the southern tip of Nevada to the Las Vegas distribution area.

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(1)	Excludes the IDRBs noted above.

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(e)

Business Experience. Information with respect to Directors is set forth under the heading “Election of Directors” in the definitive 2019 Proxy Statement, which by this reference is incorporated herein. All executive officers have held responsible positions with the Company for at least five years as described in (b) above with the exception of Paul M. Daily, Chief Executive Officer of Centuri Construction Group, Inc. Prior to his position with Centuri, Mr. Daily founded Paul M. Daily & Associates in 2014 and served as principal advisor to stakeholders in long-term planning for growth and diversification, both organically and through mergers and acquisitions. Prior to his association with Paul M. Daily & Associates, from August 2011 until September 2014, Mr. Daily co-founded and served as Director and Chief Executive Officer of Infrastructure and Energy Alternatives, LLC, which provided infrastructure design and construction services to North American energy clients.

(h)	Audit Committee Financial Expert. Information with respect to the financial expert of the Board of Directors’ audit committee is set forth under the heading “Committees of the Board” in the definitive 2019 Proxy Statement, which by this reference is incorporated herein.

(i)	Identification of the Audit Committee. Information with respect to the composition of the Board of Directors’ audit committee is set forth under the heading “Committees of the Board” in the definitive 2019 Proxy Statement, which by this reference is incorporated herein.

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(a)	Compensation Committee Interlocks and Insider Participation. Information with respect to Compensation Committee interlocks and insider participation is set forth under the heading “Governance of the Company” in the definitive 2019 Proxy Statement, which by this reference is incorporated herein.

(b)	Compensation Committee Report. Information with respect to the Compensation Committee Report is set forth under the heading “Compensation Committee Report” in the definitive 2019 Proxy Statement, which by this reference is incorporated herein.

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(1)	The number of securities to be issued upon vesting of awards includes 61,000 performance shares, which was derived by assuming that target performance will be achieved during the relevant performance period. The number of securities remaining available for future issuance includes shares relating to the Omnibus incentive plan.

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(a)	The following documents are filed as part of this report on Form 10-K:

(1)	The Consolidated Financial Statements of the Company and Southwest (including the Report of Independent Registered Public Accounting Firm) required to be reported herein are incorporated by reference to the information reported in the 2018 Annual Report to Shareholders under the following captions:

(2)	All schedules have been omitted because the required information is either inapplicable or included in the Notes to Consolidated Financial Statements.

(3)	See LIST OF EXHIBITS.

(b)	See LIST OF EXHIBITS.

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1.	Purpose of the Plan    1

2.	Definitions    1

3.	Administration    4

4.	Eligibility    6

5.	Incentive Award Opportunities    6

6.	Procedures for Calculating and Paying Actual Awards    6

7.	Performance Shares    8

8.	Participant Terminations and Transfers    9

9.	Changes in Capital Structure and Other Events    11

10.	Provisions Regarding Withholding Taxes    13

11.	Provisions Applicable to Common Stock    13

12.	Effective Date; Stockholder Approval    14

13.	Amendment and Termination of the Plan    15

14.	Benefit Claims Procedure    15

15.	General Provisions    16

1.1	“Account Balances” means a Participant’s individual fund comprised of Deferrals, Company Contributions and interest earnings credited thereon up to the applicable Benefit Distribution Date.

1.2	“Base Annual Salary” means the yearly compensation paid to an Executive, excluding bonuses, commissions, overtime, and non-monetary awards for employment services to the Company.

1.3	“Beneficiary” means the person, persons, entity or entities designated by the Participant to receive any benefits under the Plan upon the death of a Participant. A participant may designate primary and contingent Beneficiaries.

1.4	“Benefit Account Balances” shall have the meaning set forth in Article 5.1.

1.5

“Benefit Distribution Date” means the date benefits under the Plan are first paid to a Participant, or because of his death, to his Beneficiary, which will occur within 90 days of notification to the Company of the event that gives rise to such distribution. In the case of a Retirement or Termination of Employment, Benefit Distributions cannot commence until at least six months after the date of Participant’s Retirement or Termination of Employment.

1.6	“Board of Directors” means the Board of Directors of Southwest Gas Corporation and any Successor Corporation.

1.7	“Bonus” means the portion of actual awards, if any, paid in cash under the terms of the Southwest Gas Corporation 1993 Management Incentive Plan, as amended and restated (“Management Incentive Plan”).

1.8	“Change in Control” means the first to occur of any of the following events:

(a)	Any “person” (as the term is used in Sections 13 and 14(d)(2) of the Securities Exchange Act of 1934 (“Exchange Act”)) who becomes a beneficial owner (as that term is used in Section 13(d) of the Exchange Act), directly or indirectly, of 50 percent or more of the Company’s capital stock entitled to vote in the election of Directors; or

(b)

During any period of not more than twelve months, not including any period prior to the adoption of this Plan, individuals who, at the beginning of such period constitute the Board of Directors of the Company, and any new Director (other than a Director designated by a person who has entered into an agreement with the Company to effect a transaction described in clause (a) of this Article 1.8) whose election by the Board of Directors or nomination for election by the Company’s shareholders was approved by a vote of at least 75 percent of the Directors then still in office, who either were Directors at the beginning of the period or whose election or nomination for election was previously approved, cease for any reason to constitute at least a majority thereof.

1.9	“Committee” means the administrative committee appointed by the Board of Directors to manage and administer the Plan in accordance with the provisions of the Plan. After a Change in Control, the Committee shall cease to have any powers under the Plan and all powers previously vested in the Committee under the Plan will then be vested in the Third Party Fiduciary.

1.10	“Company” means Southwest Gas Corporation and such of its Subsidiaries as the Board of Directors may select to become parties to the Plan. The term “Company” shall also include any Successor Corporation.

1.11	“Company Contributions” means the amount added, if any, to a Participant’s Account Balance in accordance with Article 3.2.

1.12	“Deferral(s)” means the amount of Base Annual Salary and Bonus earned and deferred in accordance with the provisions of the Plan.

1.13	“Deferral Election Form” means the form of written agreement specifying deferral elections and a payout option which is completed and executed by the Participant and submitted to the Company in a timely manner.

1.14

“Disability” means any of the following circumstances, as determined by the Committee in its sole discretion: (a) the Participant is unable to engage in any substantial gainful activity by reason of any medically determinable physical or mental impairment which can be expected to result in death or can be expected to last for a continuous period of not less than twelve months; (b) the Participant is, by any reason of any medically determinable physical or mental impairment which can be expected to result in death or can be expected to last for a continuous period of not less than twelve months, receiving replacement benefits for a period of not less than three months under an accident and health plan covering Employees of the Company; (c) the Participant is determined to be totally disabled by the Social Security Administration; or (d) the Participant becomes eligible for and is receiving disability benefits under a long-term disability plan or program maintained by the Company, provided that the definition of “disability” applicable under such plan or program complies with the applicable requirements of the IRC.

1.15	“Employee” means any full-time employee of Southwest Gas Corporation as determined under the personnel policies and practices of Southwest Gas Corporation prior to a Change in Control.

1.16	“Executive” means any officer of Southwest Gas Corporation prior to a Change in Control.

1.17	“Master Plan Document” means this legal instrument containing the provisions of the Plan.

1.18

“Moody’s Rate” means Moody’s Seasoned Corporate Bond Rate which is an economic indicator consisting of an arithmetic average of yields of representative bonds (industrial and AAA, AA and A rated public utilities) as of January 1 prior to each Plan Year as published by Moody’s Investors Service, Inc. (or any successor thereto), or, if such index is no longer published, a substantially similar index selected by the Board of Directors.

1.19	“Moody’s Composite Rate” means the average of the Moody’s Rate on January 1 for the five years prior to the Participant’s Disability, death, Retirement or Termination of Employment, whichever event is applicable.

1.20	“Participant” means any Executive who executes a Plan Agreement or Deferral Election Form or an Employee who has been selected to participate in the Plan and who executes a Plan Agreement or Deferral Election Form.

1.21	“Plan” means the Executive Deferral Plan of the Company evidenced by this Master Plan Document.

1.22	“Plan Agreement” means the form of written agreement which is entered into by and between the Company and a Participant.

1.23	“Plan Year” means the annual period beginning on March 1 of each calendar year and ending on the last day of February of the following calendar year.

1.24	“Retire” or “Retirement” means a Participant’s separation from service with the Company on or after attaining age 55, other than by death, Disability or Termination of Employment.

1.25	“Subsidiary” means any corporation, partnership, or other organization which is at least 50 percent owned by the Company or a Subsidiary of the Company.

1.26	“Successor Corporation” means any corporation or other legal entity which is the successor to Southwest Gas Corporation, whether resulting from merger, reorganization or transfer of substantially all of the assets of Southwest Gas Corporation, regardless of whether such entity shall expressly agree to continue the Plan.

1.27	“Terminates Employment” or “Termination of Employment” means a Participant’s voluntary or involuntary separation from service with the Company, excluding Retirement, Disability or death.

1.28	“Third Party Fiduciary” means an independent third party selected by the Committee to take over the administration of the Plan upon and after a Change in Control and to determine appeals of claims denied under the Plan before and after a Change in Control pursuant to a Third Party Fiduciary Services Agreement.

1.29	“Third Party Fiduciary Services Agreement” means the agreement with the Third Party Fiduciary to perform services with respect to the Plan.

1.30	“Trust Agreement” means an agreement establishing a “grantor trust” of which the Company is the grantor, within the meaning of subpart E, part I, subchapter J, chapter 1, subtitle A of the IRC.

1.31	“Trust Fund or Funds” means the assets of every kind and description held under any Trust Agreement forming a part of the Plan.

1.32	“Trustee” means any person or entity selected by the Company to act as Trustee under any Trust Agreement at any time of reference.

1.33	“Unforeseeable Emergency” means an unforeseeable emergency as defined in the Code and related Treasury regulations.

1.34	“Years of Service” means a Participant’s Benefit Service as defined in the Retirement Plan for Employees of Southwest Gas Corporation, plus service with a Successor Corporation which is not taken into account for such plan.

2.1

Selection of Participants An Executive shall become eligible to participate in the Plan as of the effective date of his election by the Board of Directors as an officer of the Company, unless the Board of Directors determines, at that time, that such Executive will not be eligible to participate in the Plan. The Committee in its sole discretion may select any other Employee to become eligible to participate in the Plan. Notwithstanding the foregoing, no Executive or Employee shall be eligible to participate if he is not considered to be member of a “select group of management or highly compensated employees” as defined in the Employee Retirement Income Security Act of 1974, as amended (“ERISA”).

2.2

Continued Eligibility If a Participant ceases to be an Executive and he continues as an Employee, the Committee in its sole discretion will determine whether such Employee will continue to be eligible to participate in the Plan; provided, however, that any such Employee must be determined by the Committee to be a member of a “select group of management or highly compensated employees” under ERISA as a condition of his continuing eligibility to participate in the Plan. Notwithstanding the foregoing and upon the occurrence of a Change in Control, a Participant will continue to participate in the Plan.

2.3

Commencement of Participation; Conditions to Participation Once eligible to participate in the Plan, an Executive or an Employee must complete, execute and return to the Company a Plan Agreement in order to commence participation in the Plan. Continued participation in the Plan is subject to compliance with any further conditions as may be established by the Committee. Notwithstanding the foregoing and upon the occurrence of a Change in Control, no additional conditions regarding continued participation in the Plan may be established by the Committee or any Successor Corporation.

3.1

Deferrals A Participant may defer up to 100 percent of his Base Annual Salary and Bonus received during a Plan Year; provided, that such Deferral exceeds $2,000 per Plan Year. Notwithstanding the foregoing, no election shall be effective to reduce the Base Annual Salary and Bonus paid to a Participant for a calendar year to an amount which is less than the amount that the Company is required to withhold from such Participant’s Base Annual Salary and Bonus for the calendar year for (a) any income and employment taxes (including Federal Insurance Contributions Act tax), (b) contributions to any employee benefit plan (other than this Plan), and (c) payroll transfers, in place, prior to such elections.

3.2

Company Matching Contributions If a Participant makes a Deferral election with respect to Base Annual Salary and/or Bonus, the Company will contribute an amount equal to 50 percent of such Deferral, up to a maximum of three percent of the Participant’s Base Annual Salary, to the Participant’s Account Balance and, effective March 1, 2008, up to a maximum of three and one-half percent of the Participant’s Base Annual Salary, to the Participant’s Account Balance.

3.3

Benefit Payment Periods; Irrevocable Elections A Participant shall elect the period over which the amounts deferred under such election will be distributed to him commencing at the applicable Benefit Distribution Date. A Participant’s Account Balances shall be distributed in the form of substantially-equal installment payments over a period of 120, 180 or 240 months, as elected by the Participant in accordance with this Article 3.3. Only one payout option is permitted for each Plan Year. However, a Participant is free to choose any available payout option for each subsequent Plan Year. If a Participant fails to make a valid election as to the period over which his Deferrals for a particular Plan Year will be distributed, the default distribution period for such Deferrals shall be 240 months. Payout elections are irrevocable once made.

3.4	Deadline for Deferral Elections By December 31st of each calendar year, a Participant must submit to the Company his completed and executed Deferral Election Form for the upcoming Plan year. If a Participant fails to timely submit his Deferral Election Form, he will not be permitted to defer any of his Base Annual Salary or Bonus during the upcoming Plan Year.

3.5	Exercise of Deferral Election A Participant’s Deferral election will be exercised on a per pay period basis for the portion of his Base Annual Salary that is deferred. The exercise of a Participant’s Deferral election with respect to his Bonus will occur at the time the Bonus is paid.

3.6

Deferral Elections by New Participants When an Executive or an Employee first becomes eligible to participate in the Plan, initial Deferral elections will be permitted with respect to services performed after the elections, as long as such elections are made within 30 days after the date on which the Executive or Employee became eligible to participate in the Plan. Such Participant may defer up to 100 percent of the remaining portion of his Base Annual Salary for the current Plan year. Such Participant must submit his Plan Agreement to the Company, in writing, at the time he elects to become a Participant in the Plan. Thereafter, in the event an Executive or an Employee becomes a Participant in the Plan, such Participant may defer compensation only in accordance with Article 3.3.

3.7

Ineffective Elections If there shall be a final determination by the Internal Revenue Service or a court of competent jurisdiction that the election by a Participant to defer the payment of any amount in accordance with the terms of this Plan was not effective to defer the taxation of such amount, then the Participant shall be entitled to receive a distribution of the amount determined to be taxable and the Participant’s Account Balances shall be reduced accordingly.

3.8	Continuation of Deferral Election If a Participant is authorized by the Company for any reason to take a paid leave of absence, the Participant’s Deferral election shall remain in full force and effect.

3.9	Suspension of Deferral Election If a Participant is authorized by the Company for any reason to take an unpaid leave of absence, the Participant’s current Deferral election shall be terminated.

4.1

Interest Rate A Participant’s Account Balances at the start of a Plan Year and any Deferrals and Company Contributions made during a Plan Year will earn, except as provided for in Article 4.2, interest annually at 150 percent of the Moody’s Rate. Interest will be credited to a Participant’s accounts for Deferrals and Company contributions made during the Plan Year, as if all Deferrals and contributions were made on the first day of the Plan Year.

4.2	Adjustment to Interest Rate If a Participant experiences a Termination of Employment prior to completing five Years of Service with the Company, interest credited for all Deferrals and vested Company Contributions to a Participant’s Account Balances will be adjusted based on the Moody’s Rate during the period he participated in the Plan.

4.3	Vesting of Company Contributions Company Contributions and interest earned on such contributions will vest to a Participant at the rate of 20 percent per Year of Service and will vest completely once a Participant has completed five Years of Service with the Company.

4.4	Interest prior to Benefit Distribution Date A Participant’s Account Balances will earn interest under the provisions of Article 4.1 or, if applicable, Article 4.2 until the applicable Benefit Distribution Date.

4.5	Interest Rate for Benefit Payment Calculation The interest rate used to calculate the amount that will be credited to a Participant’s Account Balances to determine his Benefit Account Balances under the provisions of Article 5.1, will be 150 percent of the Moody’s Composite Rate.

5.1

Benefit Account Balances A Participant’s Account Balances, at the applicable Benefit Distribution Date, will be credited with an amount equal to the interest such balances would have earned assuming distribution in equal monthly installments over the specific benefit payment periods, at a specified interest rate, thereby creating Benefit Account Balances. The Benefit Account Balances will then be paid to the Participant in equal monthly installments over the benefit payment periods previously elected by the Participant or specified by the Plan.

6.1	Pre-Retirement Death of Participant Notwithstanding any elections made pursuant to Article 3.3 if a Participant dies while he is an employee of the Company, his Account Balances will be paid to his Beneficiary in equal monthly installments over the 180 month survivor benefit payment period commencing as of the applicable benefit commencement date.

6.2	Interest on Benefit Payments The interest rate used to determine the amount that will be credited to Participant’s Account Balances, to determine his Benefit Account Balances under the provisions of Article 5.1 following the Participant’s death, will be 150 percent of the Moody’s Composite Rate.

7.1	Post-Retirement Death of Participant If a Participant dies after the commencement of benefit payments under this Plan but prior to such benefits having been paid in full, the Participant’s benefit payments will continue to be paid to the Participant’s Beneficiary through the end of the benefit payment periods previously elected by the Participant.

8.1

Payment Following Disability Notwithstanding any elections made pursuant to Article 3.3, if a Participant becomes Disabled within the first five Years of Service with the Company, he will receive his Benefit Account Balances in a lump sum payment on the applicable Benefit Distribution Date. If a Participant becomes Disabled after having completed five or more Years of Service with the Company, the Benefit Account Balances will be paid consistent with the benefit payout periods previously elected.

8.2	Vesting of Company Contributions Notwithstanding the provisions of Article 4.3, Company contributions and interest earned on such contributions will be fully vested to the Participant at the time he is determined to be Disabled.

8.3	Interest on Benefit Payments If a Participant qualifies to receive benefits due to a Disability, the interest rate used to calculate the amount that will be credited to Participant’s Account Balances, to determine his Benefit Account Balances under the provisions of Article 5.1, will be 150 percent of the Moody’s Composite Rate.

9.1

Designation of Beneficiaries A Participant shall have the right to designate any Beneficiary to whom benefits under this Plan shall be paid in the event of the Participant’s death prior to the total distribution of his Benefit Account Balances under the Plan. If the Participant is married and greater than 50 percent of the Benefit Account Balances is designated to a Beneficiary other than the Participant’s spouse, such Beneficiary designation must be consented to by the Participant’s spouse. Each Beneficiary designation must be in written form prescribed by the Company and will be effective only when filed with the Company during the Participant’s lifetime. The Company shall acknowledge, in writing, receipt of each Beneficiary designation form.

9.2	Changing Beneficiary Designation A Participant shall have the right to change the Beneficiary designation, subject to spousal consent under the provisions of Article 9.1, without the consent of any designated Beneficiary by filing a new Beneficiary designation with the Company. The filing of a new Beneficiary designation form will cancel all Beneficiary designations previously filed.

9.3	Discharge of Company Obligation Both the Company and the Committee shall be entitled to rely on the Beneficiary designation last filed by the Participant prior to his death. Any payment made in accordance with such designation shall fully discharge the Company and the Committee from all further obligations with respect to the Participant’s rights in the Plan.

9.4

Minor or Incompetent Beneficiaries If a Beneficiary entitled to receive benefits under the Plan is a minor or a person declared incompetent, the Committee may direct payment of such benefits to the guardian or legal representative of such minor or incompetent person. The Committee may require proof of incompetency, minority or guardianship as it may deem appropriate prior to distribution of any Plan benefits. Such distribution shall completely discharge the Committee and the Company from all liability with respect to such payments.

9.5	Effect of No Beneficiary Designation If no Beneficiary designation is in effect at the time of the Participant’s death, or if the named Beneficiary predeceased the Participant, then the Beneficiary shall be: (a) the surviving spouse; (b) if there is no surviving spouse, then his issue per stirpes; or (c) if no surviving spouse or issue, then his estate.

9.6	Beneficiary’s Beneficiaries If a Participant’s Beneficiary receiving benefit payments under the provisions of the Plan dies prior to the completion of the benefit payment periods, the Participant’s benefit payments will continue to be paid through the end of the benefit payment periods previously elected by the Participant, to the Beneficiary’s Beneficiary, if any, or the applicable estate.

10.1	Payment Obligation Amounts payable to a Participant or Beneficiary shall be paid from the general assets of the Company or from the assets of a grantor trust within the meaning of subpart E, part I, subchapter J, chapter 1, subtitle A of the Code, established for use in funding executive compensation arrangements and commonly known as a “rabbi trust.”

10.2	Limitation on Payment Obligation The Company shall have no obligation under the Plan to a Participant or a Participant’s Beneficiary, except as provided in this Master Plan Document.

10.3	Furnishing Information The Participant or Beneficiary shall cooperate in furnishing all information requested by the Company to facilitate the payment of his Benefit Account Balances.

10.4

Unsecured General Creditor Participants and their Beneficiaries, heirs, successors, and assigns shall have no legal or equitable rights, claims, or interest in any specific property or assets of the Company. No assets of the Company shall be held under any trust, or held in any way as collateral security for the fulfilling of the obligations of the Company under the Plan. Any and all of the Company assets shall be, and remain, the general unpledged, unrestricted assets of the Company. The Company obligation under the Plan shall be merely that of an unfunded and unsecured promise of the Company to pay money in the future, and the rights of the Participants and Beneficiaries shall be no greater than those of unsecured general creditors. It is the intention of the Company that this Plan (and the Trust Funds described in Article 10.7) be unfunded for purposes of the Code and for the purposes of Title I of ERISA.

10.5	Withholding There shall be deducted from each payment made under the Plan or other compensation payable to the Participant (or Beneficiary) all taxes which are required to be withheld by the Company in respect to such payment under this Plan. The Company shall have the right to reduce any payment (or other compensation) by the amount of cash sufficient to provide the amount of said taxes.

10.6	Future Employment The terms and conditions of this Plan shall not be deemed to constitute a contract of employment between the Company and a Participant. Moreover, nothing in the Plan shall be deemed to give a Participant the right to be retained in the service of the Company or to interfere with the right of the Company to discipline or discharge the Participant at any time.

10.7

Trusts The Company may maintain one or more Trust Funds to finance all or a portion of the benefits under the Plan by entering into one or more Trust Agreements. Any Trust Agreement is designated as, and shall constitute, a part of the Plan, and all rights which may accrue to any person under the Plan shall be subject to all the terms and provisions of such Trust Agreement. A Trustee shall be appointed by the Committee or the Board of Directors and shall have such powers as provided in the Trust Agreement. The Committee or the Board of Directors may modify any Trust Agreement, in accordance with its terms, to accomplish the purposes of the Plan and appoint a successor Trustee under the provisions of such Trust Agreement. By entering into such Trust Agreement, the Committee or the Board of Directors may vest in the Trustee, or in one or more investment managers (as defined in ERISA) the power to manage and control the Trust Fund. Committee and the Board of Directors authority under the provisions of this Article 10.7 will cease upon the occurrence of a Change in Control.

10.8	No Assignment To the maximum extent permitted by law, no interest or benefit under the Plan shall be assignable or subject in any manner to alienation, sale, transfer, claims of creditors, pledge, attachment or encumbrances of any kind.

11.1

Plan Amendment To the extent permitted by the IRC and related regulations, the Board of Directors may, at any time, and without notice, amend or modify the Plan in whole or in part; provided, however, that (a) no amendment or modification shall be effective to decrease or restrict (i) the amount of interest to be credited to a Participant’s Account Balances under the provisions of the Plan, (ii) the benefits the Participant qualifies for or may elect to receive under the provisions of the Plan, or (iii) benefit payments to Participants or Beneficiaries once such payments have commenced, and (b) effective January 1, 2005, no amendment or modification of this Article 11, Article 12, or Article 13 of the Plan shall be effective except to the extent both the Committee and the Board of Directors deems necessary to comply with applicable law.

11.2	Plan Termination The Board of Directors shall not terminate the Plan until all benefits owed to the Participants and Beneficiaries have been paid in full.

11.3

Bankruptcy To the extent permitted under Code Section 409A and its related Treasury regulations, the Board of Directors shall have the authority, in its sole discretion, to terminate the Plan and distribute each Participant’s Account Balances to the Participant or, if applicable, his or her Beneficiary within twelve months of a corporate dissolution taxed under Section 331 of the Code or with the approval of a bankruptcy court pursuant to 11 U.S.C. §503(b)(1)(a) The total accelerated distribution under this Article 11.3 must be included in a Participant’s gross income in the latest of:

(a)	The calendar year in which the Plan is terminated;

(b)	The calendar year in which the Participant’s Account Balances are no longer subject to a substantial risk of forfeiture; or

(c)	The calendar year in which distribution of the Participant’s Account Balances is administratively practicable.

11.4

Partial Plan Termination The Board of Directors may partially terminate the Plan by instructing the Company not to accept any additional Deferral commitments. In the event of a partial termination, the remaining provisions of the Plan shall continue to operate and be effective for all Participants in the Plan, as of the date of such partial termination. Any such instructions and any reinstatement of the Plan shall be implemented in accordance with the IRC and related regulations.

11.5

Change in Control Notwithstanding any provisions herein to the contrary, in the event of a hostile or non- negotiated Change in Control (as determined by the Third Party Fiduciary, in its sole discretion), the benefits of this Plan will become 100 percent vested for all Participants and the interest credited to a Participant’s Account Balances under any provision of this Plan will be adjusted, retroactively to the date an individual became a Participant and prospectively thereafter, to 200 percent of the Moody’s Rate.

12.1

Committee Duties Except as otherwise provided in this Article 12, and subject to Article 13, the general administration of the Plan, as well as construction and interpretation thereof, shall be vested in the Committee. Members of the Committee may be Participants under the Plan. Specifically, the Committee shall have the discretion and authority to: (a) make, amend, interpret, and enforce all appropriate rules and regulations for the administration of the Plan; and (b) decide or resolve any and all questions including interpretations of the Plan. Any individual serving on the Committee who is a Participant shall not vote or act on any matter relating solely to himself or herself. The number of members of the Committee shall be established by, and the members shall be appointed from time to time by, and shall serve at the pleasure of, the Board of Directors.

12.2

Administration After a Change in Control Upon and after a Change in Control, the administration of the Plan shall be vested in a Third Party Fiduciary, as provided for herein and pursuant to the terms of a Third Party Fiduciary Services Agreement. Any Third Party Fiduciary Services Agreement is designated as, and shall constitute, a part of the Plan. The Third Party Fiduciary shall also have the discretion and authority to: (a) make, amend, interpret, and enforce all appropriate rules and regulations for the administration of the Plan; and (b) decide or resolve any and all questions including interpretation of the Plan and the Trust Agreement. Except as otherwise provided for in any Trust Agreement, the Third Party Fiduciary shall have no power to direct the investment of Plan or Trust Funds or select any investment manager or custodial firm for the Plan or Trust Agreement. The Company shall pay all reasonable administrative expenses and fees of the Third Party Fiduciary when it acts as the administrator of the Plan or pursuant to Article 13. The Third Party Fiduciary may not be terminated by the Company without the consent of at least 50 percent of the Participants in the Plan.

12.3	Agents In the administration of the Plan, the Committee or the Third Party Fiduciary, as the case may be, may from time to time employ such agents, consultants, advisors, and managers as it deems necessary or useful in carrying out its duties as it sees fit (including acting through a duly authorized representative) and may from to time to time consult with counsel to the Company.

12.4

Binding Effect of Decisions The decision or action of the Committee or the Third Party Fiduciary, as the case may be, with respect to any question arising out of or in connection with the administration, interpretation, and application of the Plan (and the Trust Agreement to the extent provided for in Article 12.2) and the rules and regulations promulgated hereunder shall be final and conclusive and binding upon all persons or entities having any interest in the Plan.

12.5

Indemnity by Company The Company shall indemnify and save harmless each member of the Committee, the Third Party Fiduciary, and any employee of the Company to whom the duties of the Committee may be delegated against any and all claims, losses, damages, expenses, and liabilities arising from any action or failure to act with respect to the Plan, except in the case of fraud, gross negligence, or willful misconduct by the Committee, any of its members, the Third Party Fiduciary, or any such employee.

12.6

Cooperation – Providing Information To enable the Committee and the Third Party Fiduciary to perform their functions, the Company shall supply full and timely information to the Committee and the Third Party Fiduciary, as the case may be, on all matters relating to the compensation of all Participants, their Retirement, death, Disability or other cause for Termination of Employment, and such other pertinent facts as the Committee or the Third Party Fiduciary may require.

12.7

Unforeseeable Emergencies In the event of an Unforeseeable Emergency, the Committee or the Third Party Fiduciary, as the case may be, may in its sole discretion, permit distribution to a Participant or Beneficiary from this Plan an amount no greater than the amount necessary to satisfy the Unforeseeable Emergency plus any taxes reasonably anticipated as a result of the distribution; or permit a Participant to cancel his or her Deferral election for the applicable Plan Year in accordance with applicable Treasury regulations without an accompanying distribution from his or her Account Balances. A Participant’s current Deferral election, if any, shall automatically terminate upon such Participant’s receipt of a withdrawal under this Article 12.7 or upon such Participant’s receipt of a “hardship distribution” (within the meaning of Code Section 401(k)(2)(B)(IV) and the related Treasury regulations) under any of the Company tax-qualified retirement plans. To the extent such a Participant again becomes eligible to elect Deferrals in accordance with the terms of the Plan, any subsequent Deferral elections made by the Participant must be made in accordance with the provisions of Article 3.

13.1	Presentation of Claims Any Participant or Beneficiary of a deceased Participant (such Participant or Beneficiary being referred to below as a “Claimant”) may deliver to the Committee a written claim for determination with respect to benefits available to such Claimant from the Plan. The claim must state with particularity the determination desired by the Claimant.

13.2	Notification of Decision The Committee shall consider a claim and notify the Claimant within 90 calendar days after receipt of a claim in writing:

(a)	That the Claimant’s requested determination has been made, and that the claim has been allowed in full; or

(b)

That the Committee has reached a conclusion contrary, in whole or in part, to the Claimant’s requested determination, and such notice must set forth in a manner calculated to be understood by the Claimant: (i) the specific reason(s) for the denial of the claim, or any part thereof; (ii) the specific reference(s) to pertinent provisions of the Plan upon which the denial was based; (iii) a description of any additional material or information necessary for the Claimant to perfect the claim, and an explanation of why such material or information is necessary; and (iv) an explanation of the claim review procedure set forth in Article 13.3.

13.3

Review of a Denied Claim Within 60 days after receiving a notice from the Committee that a claim has been denied, in whole or in part, a Claimant (or the Claimant’s duly authorized representative) may file with the Third Party Fiduciary a written request for a review of the denial of the claim. Thereafter, the Claimant (or the Claimant’s duly authorized representative) may review pertinent documents, submit written comments or other documents, and request a hearing, which the Third Party Fiduciary, in its sole discretion, may grant.

13.4

Decision on Review The Third Party Fiduciary shall render its decision on review promptly, and not later than 60 days after the filing of a written request for review of a denial, unless a hearing is held or other special circumstances require additional time, in which case the Third Party Fiduciary’s decision must be rendered within 120 calendar days after such date. Such decision must be written in a manner calculated to be understood by the Claimant, and it must contain: (a) the specific reason(s) for the decision; (b) the specific reference(s) to the pertinent Plan provisions upon which the decision was based; and (c) such other matters as the Third Party Fiduciary deems relevant.

13.5	Legal Action A Claimant’s compliance with the foregoing provisions of this Article 18 is a mandatory prerequisite to a Claimant’s right to commence any legal action with respect to any claim for benefits under the Plan.

14.1	Notices Any notice given under the Plan shall be in writing and shall be mailed or delivered to:

14.2	Assignment The Plan shall be binding upon the Company and any of its successors and assigns, and upon a Participant, a Participant’s Beneficiary, and their assigns, heirs, executors and administrators.

14.3	Governing Law Except to the extent that federal law applies, the Plan shall be governed by and construed under the laws of the State of Nevada.

14.4	Headings Headings in this Master Plan Document are inserted for convenience of reference only. Any conflict between such headings and the text shall be resolved in favor of the text.

14.5	Gender and Number Masculine pronouns wherever used shall include feminine pronouns and when the context dictates, the singular shall include the plural.

14.6	Severability In case any provision of the Plan shall be held illegal or invalid for any reason, said illegality or invalidity shall not affect the remaining parts hereof, but the Plan shall be construed and enforced as if such illegal and invalid provisions had never been inserted herein.

1.1	“Account Balance” means a Participant’s individual fund comprised of Deferrals, Company Contributions and interest earnings credited thereon up to the time of Benefit Distribution exclusive of Excess Earnings.

1.2	“Base Annual Salary” means the yearly compensation paid to an Executive, excluding bonuses, commissions, overtime, and non-monetary awards for employment services to the Company.

1.3	“Beneficiary” means the person, persons, entity or entities designated by the Participant to receive any benefits under the Plan upon the death of a Participant. A Participant may designate primary and contingent Beneficiaries.

1.4	“Benefit Account Balance” shall have the meaning set forth in Article 5.3.

1.5	“Benefit Distribution” means the date benefits under the Plan commence or are paid in full to a Participant, or because of his death, to his Beneficiary, which will occur within 90 days of notification to the Company of the event that gives rise to such distribution.

1.6	“Board of Directors” means the Board of Directors of Southwest Gas Corporation and any Successor Corporation.

1.7	“Bonus” means the portion of actual awards, if any, paid in cash under the terms of Southwest Gas Corporation’s 1993 Management Incentive Plan, as amended (“Management Incentive Plan”).

1.8	“Change in Control” means the first to occur of any of the following events:

(a)	Any “person” (as the term is used in Sections 13 and 14(d)(2) of the Securities Exchange Act of 1934 (“Exchange Act”)) who becomes a beneficial owner (as that term is used in Section 13(d) of the Exchange Act), directly or indirectly, of 50 percent or more of the Company’s capital stock entitled to vote in the election of Directors; or

(b)

During any period of not more than twelve months, not including any period prior to the adoption of this Plan, individuals who, at the beginning of such period constitute the Board of Directors of the Company, and any new Director (other than a Director designated by a person who has entered into an agreement with the Company to effect a transaction described in clause (a) of this Article 1.8) whose election by the Board of Directors or nomination for election by the Company’s shareholders was approved by a vote of at least 75 percent of the Directors then still in office, who either were Directors at the beginning of the period or whose election or nomination for election was previously approved, cease for any reason to constitute at least a majority thereof.

1.9	“Committee” means the administrative committee appointed by the Board of Directors to manage and administer the Plan in accordance with the provisions of the Plan. After a Change in Control, the Committee shall cease to have any powers under the Plan and all powers previously vested in the Committee under the Plan will then be vested in the Third Party Fiduciary.

1.10	“Company” means Southwest Gas Corporation and such of its Subsidiaries as the Board of Directors may select to become parties to the Plan. The term “Company” shall also include any Successor Corporation.

1.11	“Company Contributions” means the amount added, if any, to a Participant’s Account Balance in accordance with Article 3.2.

1.12	“Deferral(s)” means the amount of Base Annual Salary and Bonus transferred to the Plan accounts. No Deferrals will be accepted into this Plan after December 31, 2004.

1.13	“Employee” means any full-time employee of Southwest Gas Corporation as determined under the personnel policies and practices of Southwest Gas Corporation prior to a Change in Control.

1.14

“Excess Earnings” means any interest accruing on a Participant’s Account Balance on or after January 1, 2009 that would itself be considered to be a right to deferred compensation (within the meaning of Code Section 409A and related Treasury regulations) rather than a right to earnings on Deferrals of compensation. For purposes of clarification, Excess Earnings shall include any earnings in excess of 100 percent of the Moody’s Rate credited to Participant Accounts on or after January 1, 2009. For purposes of Plan accounting, Excess Earnings shall be segregated from interest credited on Account Balances under Article 4 and credited to Participant Excess Earnings Accounts.

1.15	“Excess Earnings Account” means the separate account to which a Participant’s Excess Earnings are credited.

1.16	“Executive” means any officer of Southwest Gas Corporation prior to a Change in Control.

1.17	“Master Plan Document” means this legal instrument containing the provisions of the Plan.

1.18

“Moody’s Rate” means Moody’s Seasoned Corporate Bond Rate which is an economic indicator consisting of an arithmetic average of yields of representative bonds (industrial and AAA, AA and A rated public utilities) as of January 1 prior to each Plan Year as published by Moody’s Investors Service, Inc. (or any successor thereto), or, if such index is no longer published, a substantially similar index selected by the Board of Directors.

1.19	“Moody’s Composite Rate” means the average of the Moody’s Rate on January 1 for the five years prior to Benefit Distribution.

1.20	“Participant” means any Executive who executes a Plan Agreement or an Employee who has been selected to participate in the Plan and who executes a Plan Agreement. No new Participants will be accepted into this Plan after December 31, 2004.

1.21	“Plan” means the Executive Deferral Plan of the Company evidenced by this Master Plan Document.

1.22	“Plan Agreement” means the form of written agreement which is entered into from time to time, by and between the Company and a Participant.

1.23	“Plan Year” means the year beginning on March 1 of each year.

1.24	“Retire” or “Retirement” means the severance from employment with the Company on or after attaining age 55, other than by death, disability or Termination of Employment.

1.25	“Subsidiary” means any corporation, partnership, or other organization which is at least 50 percent owned by the Company or a Subsidiary of the Company.

1.26	“Successor Corporation” means any corporation or other legal entity which is the successor to Southwest Gas Corporation, whether resulting from merger, reorganization or transfer of substantially all of the assets of Southwest Gas Corporation, regardless of whether such entity shall expressly agree to continue the Plan.

1.27	“Terminates Employment” or “Termination of Employment” means the ceasing of employment with the Company, either voluntarily or involuntarily, excluding Retirement, disability or death.

1.28	“Third Party Fiduciary” means an independent third party selected by the Committee to take over the administration of the Plan upon and after a Change in Control and to determine appeals of claims denied under the Plan before and after a Change in Control pursuant to a Third Party Fiduciary Services Agreement.

1.29	“Third Party Fiduciary Services Agreement” means the agreement with the Third Party Fiduciary to perform services with respect to the Plan.

1.30	“Trust Agreement” means an agreement establishing a “grantor trust” of which the Company is the grantor, within the meaning of subpart E, part I, subchapter J, chapter 1, subtitle A of the IRC.

1.31	“Trust Fund or Funds” means the assets of every kind and description held under any Trust Agreement forming a part of the Plan.

1.32	“Trustee” means any person or entity selected by the Company to act as Trustee under any Trust Agreement at any time of reference.

1.33	“Years of Service” means a Participant’s Benefit Service as defined in the Retirement Plan for Employees of Southwest Gas Corporation, plus service with a Successor Corporation which is not taken into account for such plan.

2.1

Selection of Participants An Executive shall become eligible to participate in the Plan as of the effective date of his election by the Board of Directors as an officer of the Company (unless the Board of Directors determines, at that time, that such Executive will not become eligible to participate in the Plan). The Committee in its sole discretion may select any other Employee to become eligible to participate in the Plan.

2.2	Continued Eligibility If a Participant ceases to be an Executive and he continues as an Employee, the Committee in its sole discretion will determine whether such Employee will continue to be eligible to participate in the Plan. Notwithstanding the foregoing and upon the occurrence of a Change in Control, a Participant will continue to participate in the Plan.

2.3

Participant Acceptance Once eligible to participate in the Plan, an Executive or an Employee has to complete, execute and return to the Committee a Plan Agreement to become a Participant in the Plan. Continued participation in the Plan is subject to compliance with any further conditions as may be established by the Committee. Notwithstanding the foregoing and upon the occurrence of a Change in Control, no additional conditions regarding continued participation in the Plan may be established by the Committee or any Successor Corporation.

3.1

Deferrals A Participant may defer up to 100 percent of his Base Annual Salary and Bonus received during a Plan Year; provided that such Deferral exceeds $2,000 per Plan Year. Notwithstanding the foregoing, no election shall be effective to reduce the Base Annual Salary and Bonus paid to a Participant for a calendar year to an amount which is less than the amount that the Company is required to withhold from such Participant’s Base Annual Salary and Bonus for the calendar year for (a) applicable income and employment taxes (including Federal Insurance Contributions Act tax), (b) contributions to any employee benefit plan (other than this Plan), and (c) payroll transfers, in place, prior to such elections.

3.2	Company Matching Contributions If a Participant makes a Deferral commitment with respect to Base Annual Salary and/or Bonus, the Company will contribute an amount equal to 50 percent of such Deferral, up to a maximum of three percent of the Participant’s Base Annual Salary, to the Participant’s Account Balance.

3.3

Timing of Deferral Election Prior to the commencement of each Plan Year, a Participant will (a) advise the Committee, in writing, of his Base Annual Salary Deferral commitment for the upcoming Plan Year and (b) make his Deferral commitment for any Bonus earned during the calendar year ending in such Plan Year. If a Participant fails to so advise the Committee, through no fault of the Company, he will not be permitted to defer any of his Base Annual Salary or Bonus during the upcoming Plan Year.

3.4	Exercise of Deferral Commitment A Participant’s Deferral commitment will be exercised on a per pay period basis for the portion of his Base Annual Salary that is deferred. The exercise of a Participant’s Deferral commitment with respect to his Bonus will occur at the time the Bonus is paid.

3.5	Adjustment to Deferral Commitment The Committee reserves the right to adjust any Participant’s Deferral commitment during a Plan Year to ensure that a Participant’s actual Deferral does not exceed the maximum allowable amount.

3.6

Deferral Elections by New Participants In the event an Executive or an Employee becomes a Participant in the Plan during a Plan Year, such Participant may defer up to 100 percent of the remaining portion of his Base Annual Salary for the current Plan Year. Such Participant must make his Deferral commitment by advising the Committee, in writing, at the time he elects to become a Participant in the Plan.

3.7

Deferral Commitment Default In the event a Participant defaults on his Base Annual Salary Deferral commitment, the Participant will not be allowed to make any further Deferrals during the current Plan Year and may not make any Deferrals for the subsequent Plan Year. In the event a Participant defaults on his Bonus Deferral commitment for a particular Plan Year, the Participant will not be able to defer any of his Bonus for that Plan Year or the subsequent Plan Year.

3.8	Waiver of Deferral Commitment Default The Committee may waive for good cause the default penalty specified in Article 3.7 upon the request of the Participant.

3.9	Deferrals after December 31, 2004 Notwithstanding any provision herein to the contrary, no Deferrals or Company matching contributions will be accepted into this Plan after December 31, 2004, and no new Participants will be admitted hereunder after December 31, 2004. Excess Earnings shall continue to be credited under the Plan.

4.1

Interest Rate A Participant’s Account Balance at the start of a Plan Year and any Deferrals and Company contributions made during a Plan Year will earn, except as provided for in Article 4.2, interest annually at 150 percent of the Moody’s Rate. Interest will be credited to a Participant’s account for Deferrals and Company contributions made during the Plan Year, as if all Deferrals and contributions were made on the first day of the Plan Year.

4.2	Adjustment to Interest Rate If a Participant Terminates Employment prior to completing five Years of Service with the Company, interest credited for all Deferrals and vested Company contributions to a Participant’s Account Balance will be adjusted based on the Moody’s Rate during the period he participated in the Plan.

4.3	Vesting of Company Contributions Company contributions and interest earned on such contributions will vest to a Participant at the rate of 20 percent per Year of Service and will vest completely once a Participant has five Years of Service with the Company.

4.4	Interest Earned after December 31, 2004 Interest earned on Deferrals made on or before December 31, 2004 will be credited to the Participant’s Account Balance in accordance with this Article 4. Any such interest, exclusive of Excess Earnings, is intended to be regarded as attributable to amounts deferred under the Plan as of December 31, 2004.

5.1	Lump-Sum Payment A Participant’s Account Balance will be paid to the Participant in a lump-sum payment at the time of Benefit Distribution, unless the Participant qualifies to receive benefit payments over a specific benefit payment period.

5.2	Interest prior to Benefit Distribution A Participant’s Account Balance will earn interest under the provisions of Article 4.1 or, if applicable, Article 4.2 until the time of Benefit Distribution.

5.3

Benefit Payment Periods If a Participant is entitled to receive Plan benefit payments over a specific benefit payment period, his Account Balance at the commencement of Benefit Distribution will be credited with an amount equal to the interest such balance would have earned assuming distribution in equal monthly installments over the specific benefit payment period, at a specified interest rate, thereby creating a Benefit Account Balance. Such Benefit Account Balance shall exclude any amounts credited to a Participant’s Excess Earnings Account. The Benefit Account Balance will then be paid to the Participant in equal monthly installments over the specific benefit payment period.

5.4

Payment Prior to Benefit Distribution If there shall be a final determination by the Internal Revenue Service or a court of competent jurisdiction that the election by a Participant to defer the payment of any amount in accordance with the terms of this Plan was not effective to defer the taxation of such amount, then the Participant shall be entitled to receive a distribution of the amount determined to be taxable and the Participant’s Account Balance shall be reduced accordingly.

5.5	Six Month Delay for Excess Earnings Account In the case of a Retirement or Termination of Employment, Benefit Distributions from the Participant’s Excess Earnings Account cannot commence until at least six months after the date of Participant’s Retirement or Termination of Employment.

6.1

Benefit Payment Periods; Elections A Participant who Retires or Terminates Employment with more than five Years of Service qualifies to receive his Account Balance over a period of 120, 180 or 240 months. The Participant shall elect the payment period; provided that written notice of such election is filed with the Committee at least one year prior to his Retirement or Termination of Employment. If a Participant fails to make such election prior to the time specified, the payment period will be 240 months. A Participant will be deemed to have elected to receive his Excess Earnings Account balance upon his Retirement or Termination of Service on the same payment schedule that is applicable to his Account Balance; provided, however, that a Participant’s Excess Earnings Account shall not commence to be distributed upon a Retirement or Termination of Service that is not also a “separation from service” within the meaning of Code Section 409A of the Treasury regulations.

6.2

Changing Elections A Participant who has made an election under this Article may subsequently revoke such election and make another election under this Article by providing written notice to the Committee; provided, however, that only the last such election or revocation in effect on the date which is one year prior to the date on which the Participant Retires or Terminates Employment shall be effective. Notwithstanding the foregoing, if a Participant Terminates Employment or Retires as a result of a Change in Control, the foregoing provisions of this Article 6 shall be applied by substituting “six months” for “one year.” In the event of any such amended election, the Participant’s election in effect at January 1, 2009 shall remain in effect without modification for the Excess Earnings Account.

6.3	Interest on Benefit Payments The interest rate used to calculate the amount that will be credited to a Participant’s Account Balance, to determine his Benefit Account Balance under the provisions of Article 5.3, will be 150 percent of the Moody’s Composite Rate. Any Excess Earnings attributable to such interest credit shall be segregated and allocated to the Participant’s Excess Earnings Account.

7.1	Benefit Payments Notwithstanding any elections made pursuant to Article 6, if a Participant dies while he is an employee of the Company, both his Account Balance and his Excess Earnings Account balance will be paid to his Beneficiary in equal monthly installments over the 180 month survivor benefit payment period.

7.2

Interest on Benefit Payments The interest rate used to determine the amount that will be credited to a Participant’s Account Balance, to determine his Benefit Account Balance under the provisions of Article 5.3 following the Participant’s death, will be 150 percent of the Moody’s Composite Rate. Any Excess Earnings attributable to such interest credit shall be segregated and allocated to the Participant’s Excess Earnings Account.

8.1

Benefit Payments If a Participant dies after the commencement of Retirement, Termination of Employment or disability benefit payments under Articles 6 or 9 but prior to such benefits having been paid in full, the Participant’s benefit payments will continue to be paid to the Participant’s Beneficiary through the end of the originally awarded benefit payment period, except as provided for in Article 10.7.

9.1

Disability Determination A Participant shall be considered disabled if he qualifies for a disability benefit under the Company’s group long-term disability plan. In the event a Participant does not qualify for benefits under the group long-term disability plan, the Committee may determine that a Participant is disabled under the provisions of the Plan; provided, however, that no distribution of a Participant’s Excess Earnings Account shall be triggered by a disability that is not also a “disability” within the meaning of Code Section 409A of the Treasury regulations.

9.2	Vesting of Company Contributions Notwithstanding the provisions of Article 4.3, Company contributions and interest earned on such contributions will be fully vested to the Participant at the time he is determined to be disabled under this Article.

9.3	Benefit Payments During First Five Years of Service If a Participant is disabled within the first five Years of Service with the Company, he will receive his Account Balance and Excess Earnings Account balance in a lump sum payment at Benefit Distribution.

9.4	Benefit Payments After Five Years of Service Notwithstanding any elections made pursuant to Article 6, if a Participant is disabled after five Years of Service with the Company, his Account Balance and Excess Earnings Account balance will be paid to him in equal monthly installments over the 180 month disability payment period.

9.5

Interest on Benefit Payments If a Participant qualifies to receive his Account Balance and Excess Earnings Account balance over the disability benefit payment period, the interest rate used to calculate the amount that will be credited to a Participant’s Account Balance, to determine his Benefit Account Balance under the provisions of Article 5.3, will be 150 percent of the Moody’s Composite Rate. Any Excess Earnings attributable to such interest credit shall be segregated and allocated to the Participant’s Excess Earnings Account.

10.1

Designation of Beneficiaries A Participant shall have the right to designate any Beneficiary to whom benefits under this Plan shall be paid in the event of the Participant’s death prior to the total distribution of his Benefit Account Balance under the Plan. If greater than 50 percent of the Benefit Account Balance is designated to a Beneficiary other than the Participant’s spouse, such Beneficiary designation must be consented to by the Participant’s spouse. Each Beneficiary designation must be in written form prescribed by the Committee and will be effective only when filed with the Committee during the Participant’s lifetime.

10.2	Changing Beneficiary Designation A Participant shall have the right to change the Beneficiary designation, subject to spousal consent under the provisions of Article 10.1, without the consent of any designated Beneficiary by filing a new Beneficiary designation with the Committee. The filing of a new Beneficiary designation form will cancel all Beneficiary designations previously filed.

10.3	Acknowledgment The Committee shall acknowledge, in writing, receipt of each Beneficiary designation form.

10.4	Discharge of Company Obligation The Committee shall be entitled to rely on the Beneficiary designation last filed by the Participant prior to his death. Any payment made in accordance with such designation shall fully discharge the Company from all further obligations with respect to the amount of such payments.

10.5

Minor or Incompetent Beneficiaries If a Beneficiary entitled to receive benefits under the Plan is a minor or a person declared incompetent, the Committee may direct payment of such benefits to the guardian or legal representative of such minor or incompetent person. The Committee may require proof of incompetency, minority or guardianship as it may deem appropriate prior to distribution of any Plan benefits. Such distribution shall completely discharge the Committee and the Company from all liability with respect to such payments.

10.6	Effect of No Beneficiary Designation If no Beneficiary designation is in effect at the time of the Participant’s death, or if the named Beneficiary predeceased the Participant, then the Beneficiary shall be: (a) the surviving spouse; (b) if there is no surviving spouse, then his issue per stirpes; or (c) if no surviving spouse or issue, then his estate.

10.7

Payment to Beneficiary’s Beneficiary If a Beneficiary receiving benefit payments under the provisions of the Plan dies prior to the completion of the benefit payment period, the present value of the remaining benefit payments will be paid, in a lump sum amount, to the Beneficiary’s Beneficiary, if any, or to the applicable estate. The payment of the Participant’s Excess Earnings Account balance shall continue to be paid through the end of the benefit payment period previously elected by the Participant or specified by the Plan. The present value of the remaining benefit payments will be calculated using the same methodology, including the same interest rate, as was used to calculate the Participant’s annuity payment calculation, under Article 5.3.

11.1	Continuation of Deferral Commitment If a Participant is authorized by the Company for any reason to take a paid leave of absence, the Participant’s Deferral commitment shall remain in full force and effect.

11.2	Suspension of Deferral Commitment If a Participant is authorized by the Company for any reason to take an unpaid leave of absence, the Participant’s Deferral commitment shall be suspended until the leave of absence ends and the Participant’s employment resumes.

12.1	Payment Obligation Amounts payable to a Participant or Beneficiary shall be paid from the general assets of the Company or from the assets of a grantor trust within the meaning of subpart E, part I, subchapter J, chapter 1, subtitle A of the Code, established for use in funding executive compensation arrangements and commonly known as a “rabbi trust.”

12.2	Limitation on Payment Obligation The Company shall have no obligation under the Plan to a Participant or a Participant’s Beneficiary, except as provided in this Master Plan Document.

12.3	Furnishing Information The Participant or Beneficiary must cooperate with the Committee in furnishing all information requested by the Company to facilitate the payment of his Benefit Account Balance. Such information may include the results of a physical examination if any is required for participation in the Plan.

12.4

Unsecured General Creditor Participants and their Beneficiaries, heirs, successors, and assigns shall have no legal or equitable rights, claims, or interest in any specific property or assets of the Company. No assets of the Company shall be held under any trust, or held in any way as collateral security for the fulfilling of the obligations of the Company under the Plan. Any and all of the Company’s assets shall be, and remain, the general unpledged, unrestricted assets of the Company. The Company’s obligation under the Plan shall be merely that of an unfunded and unsecured promise of the Company to pay money in the future, and the rights of the Participants and Beneficiaries shall be no greater than those of unsecured general creditors. It is the intention of the Company that this Plan (and the Trust Funds described in Article 14.1) be unfunded for purposes of the Code and for the purposes of Title I of the Employee Retirement Income Security Act of 1974, as amended (“ERISA”).

12.5	Withholding There shall be deducted from each payment made under the Plan or other compensation payable to the Participant or Beneficiary all taxes which are required to be withheld by the Company in respect to such payment or this Plan. The Company shall have the right to reduce any payment (or other compensation) by the amount of cash sufficient to provide the amount of said taxes.

13.1	Future Employment The terms and conditions of this Plan shall not be deemed to constitute a contract of employment between the Company and a Participant. Moreover, nothing in the Plan shall be deemed to give a Participant the right to be retained in the service of the Company or to interfere with the right of the Company to discipline or discharge the Participant at any time.

14.1

Trusts The Company may maintain one or more Trust Funds to finance all or a portion of the benefits under the Plan by entering into one or more Trust Agreements. Any Trust Agreement is designated as, and shall constitute, a part of the Plan, and all rights which may accrue to any person under the Plan shall be subject to all the terms and provisions of such Trust Agreement. A Trustee shall be appointed by the Committee or the Board of Directors and shall have such powers as provided in the Trust Agreement. The Committee or the Board of Directors may modify any Trust Agreement, in accordance with its terms, to accomplish the purposes of the Plan and appoint a successor Trustee under the provisions of such Trust Agreement. By entering into such Trust Agreement, the Committee or the Board of Directors may vest in the Trustee, or in one or more investment managers (as defined in ERISA) the power to manage and control the Trust Fund. The Committee’s authority under the provisions of this Article 14.1 will cease upon the occurrence of a Change in Control.

15.1

Plan Amendments The Board of Directors may, at any time, without notice, amend or modify the Plan in whole or in part; provided, however, that (a) no amendment or modification shall be effective to decrease or restrict (i) the amount of interest to be credited to a Participant’s Account Balance under the provisions of the Plan, (ii) the benefits the Participant qualifies for or may elect to receive under the provisions of the Plan, or (iii) benefit payments to Participants or Beneficiaries once such payments have commenced, and (b) effective March 1, 1999, no amendment or modification of this Article 15, Article 17, or Article 18 of the Plan shall be effective except to the extent the Board of Directors deems necessary or appropriate to comply with applicable law.

15.2	Plan Termination The Board of Directors shall not terminate the Plan until all accrued benefits have been paid in full under the provisions of the Plan to the Participants and Beneficiaries.

15.3	Partial Plan Termination The Board of Directors may partially terminate the Plan by instructing the Committee not to accept any additional Deferral commitments. In the event of a partial termination, the remaining provisions of the Plan shall continue to operate and be effective for all Participants in the Plan, as of the date of such partial termination.

15.4

Change of Control In the event of a hostile or non-negotiated Change of Control of the Company, the benefits of this Plan will become 100 percent vested for all Participants and the interest credited to a Participant’s Account Balance under any provision of this Plan will be adjusted, retroactively to the date an individual became a Participant and prospectively thereafter, to 200 percent of the Moody’s Rate; provided, however, that any Excess Earnings attributable to such interest credit shall be segregated and allocated to the Participant’s Excess Earnings Account.

16.1	Alienation of Benefits To the maximum extent permitted by law, no interest or benefit under the Plan shall be assignable or subject in any manner to alienation, sale, transfer, claims of creditors, pledge, attachment or encumbrances of any kind.

17.1

Committee Duties Except as otherwise provided in this Article 17, and subject to Article 18, the general administration of the Plan, as well as construction and interpretation thereof, shall be vested in the Committee. Members of the Committee may be Participants under the Plan. Specifically, the Committee shall have the discretion and authority to: (a) make, amend, interpret, and enforce all appropriate rules and regulations for the administration of the Plan; and (b) decide or resolve any and all questions including interpretations of the Plan. Any individual serving on the Committee who is a Participant shall not vote or act on any matter relating solely to himself or herself. The number of members of the Committee shall be established by, and the members shall be appointed from time to time by, and shall serve at the pleasure of, the Board of Directors.

17.2

Administration After a Change in Control Upon and after a Change in Control, the administration of the Plan shall be vested in a Third Party Fiduciary, as provided for herein and pursuant to the terms of a Third Party Fiduciary Services Agreement. Any Third Party Fiduciary Services Agreement is designated as, and shall constitute, a part of the Plan. The Third Party Fiduciary shall also have the discretion and authority to: (a) make, amend, interpret, and enforce all appropriate rules and regulations for the administration of the Plan; and (b) decide or resolve any and all questions including interpretation of the Plan and the Trust Agreement. Except as otherwise provided for in any Trust Agreement, the Third Party Fiduciary shall have no power to direct the investment of Plan or Trust Funds or select any investment manager or custodial firm for the Plan or Trust Agreement. The Company shall pay all reasonable administrative expenses and fees of the Third Party Fiduciary when it acts as the administrator of the Plan or pursuant to Article 18. The Third Party Fiduciary may not be terminated by the Company without the consent of 50 percent of the Participants in the Plan.

17.3	Agents In the administration of the Plan, the Committee or the Third Party Fiduciary, as the case may be, may from time to time employ such agents, consultants, advisors, and managers as it deems necessary or useful in carrying out its duties as it sees fit (including acting through a duly authorized representative) and may from to time to time consult with counsel to the Company.

17.4

Binding Effect of Decisions The decision or action of the Committee or the Third Party Fiduciary, as the case may be, with respect to any question arising out of or in connection with the administration, interpretation, and application of the Plan (and the Trust Agreement to the extent provided for in Article 17.2) and the rules and regulations promulgated hereunder shall be final and conclusive and binding upon all persons having any interest in the Plan.

17.5

Indemnity by Company The Company shall indemnify and save harmless each member of the Committee, the Third Party Fiduciary, and any employee of the Company to whom the duties of the Committee may be delegated against any and all claims, losses, damages, expenses, and liabilities arising from any action or failure to act with respect to the Plan, except in the case of fraud, gross negligence, or willful misconduct by the Committee, any of its members, the Third Party Fiduciary, or any such employee.

17.6

Employer Information. To enable the Committee and the Third Party Fiduciary to perform their functions, the Company shall supply full and timely information to the Committee and the Third Party Fiduciary, as the case may be, on all matters relating to the compensation of all Participants, their Retirement, death or other cause for Termination of Employment, and such other pertinent facts as the Committee or the Third Party Fiduciary may require.

17.7

Manner and Timing of Benefit Payments The Committee or the Third Party Fiduciary, as the case may be, may alter, at or after Benefit Distribution, the manner and time of payments to be made to a Participant or Beneficiary from that set forth herein, if requested to do so by such Participant or Beneficiary to meet existing financial hardships, which the Committee or the Third Party Fiduciary, as the case may be, determine are the same as or similar in nature to those identified in Section 1.401(k)-1(d)(2)(iv) of the Treasury regulations.

18.1	Presentation of Claims Any Participant or Beneficiary of a deceased Participant (such Participant or Beneficiary being referred to below as a “Claimant”) may deliver to the Committee a written claim for determination with respect to benefits available to such Claimant from the Plan. The claim must state with particularity the determination desired by the Claimant.

18.2	Notification of Decision The Committee shall consider a claim and notify the Claimant within 90 calendar days after receipt of a claim in writing:

(a)	That the Claimant’s requested determination has been made, and that the claim has been allowed in full; or

(b)

That the Committee has reached a conclusion contrary, in whole or in part, to the Claimant’s requested determination, and such notice must set forth in a manner calculated to be understood by the Claimant: (i) the specific reason(s) for the denial of the claim, or any part thereof; (ii) the specific reference(s) to pertinent provisions of the Plan upon which the denial was based; (iii) a description of any additional material or information necessary for the Claimant to perfect the claim, and an explanation of why such material or information is necessary; and (iv) an explanation of the claim review procedure set forth in Article 18.3.

18.3

Review of a Denied Claim Within 60 days after receiving a notice from the Committee that a claim has been denied, in whole or in part, a Claimant (or the Claimant’s duly authorized representative) may file with the Third Party Fiduciary a written request for a review of the denial of the claim. Thereafter, the Claimant (or the Claimant’s duly authorized representative) may review pertinent documents, submit written comments or other documents, and request a hearing, which the Third Party Fiduciary, in its sole discretion, may grant.

18.4

Decision on Review The Third Party Fiduciary shall render its decision on review promptly, and not later than 60 days after the filing of a written request for review of a denial, unless a hearing is held or other special circumstances require additional time, in which case the Third Party Fiduciary’s decision must be rendered within 120 calendar days after such date. Such decision must be written in a manner calculated to be understood by the Claimant, and it must contain: (a) the specific reason(s) for the decision; (b) the specific reference(s) to the pertinent Plan provisions upon which the decision was based; and (b) such other matters as the Third Party Fiduciary deems relevant.

18.5	Legal Action A Claimant’s compliance with the foregoing provisions of this Article 18 is a mandatory prerequisite to a Claimant’s right to commence any legal action with respect to any claim for benefits under the Plan.

19.1	Notice Any notice given under the Plan shall be in writing and shall be mailed or delivered to:

19.2	Assignment The Plan shall be binding upon the Company and any of its successors and assigns, and upon a Participant, a Participant’s Beneficiary, and their assigns, heirs, executors and administrators.

19.3	Governing Laws Except to the extent that federal law applies, the Plan shall be governed by and construed under the laws of the State of Nevada.

19.4	Headings Headings in this Master Plan Document are inserted for convenience of reference only. Any conflict between such headings and the text shall be resolved in favor of the text.

19.5	Gender and Number Masculine pronouns wherever used shall include feminine pronouns and when the context dictates, the singular shall include the plural.

19.6	Effect of Illegality or Invalidity In case any provision of the Plan shall be held illegal or invalid for any reason, said illegality or invalidity shall not affect the remaining parts hereof, but the Plan shall be construed and enforced as if such illegal and invalid provisions had never been inserted herein.

*

Awards granted pursuant to the Plan will range from 50 percent to 150 percent of the target Award opportunity for each participant, other than non-Employee Directors, established for the initial Award. The actual Award will be determined based on the three-year average Management Incentive Plan payout percentage (the “MIP Payout Percentage”) for the three years immediately preceding the Award determination date. The threshold to earn an Award will be a MIP Payout Percentage of 90. The Award will increase by five percent for each one percentage point increase in the MIP Payout Percentage until such percentage equals 100, then the increase will be reduced to two and one-half percent for each percentage point increase through 120.

*	Awards granted pursuant to the Plan to Directors will be set at 800 Restricted Stock or Stock Units per year.

*	Once the Awards are established, they will be converted into Restricted Stock or Stock Units, based on the average of the closing prices of the Common Stock on the New York Stock Exchange for the first five trading days of the month in which the award is granted.

(a)

Forty percent (40%) of the Units subject to each annual Award shall vest on the 4th of January following the award (the “Vesting Commencement Date”), and thirty percent (30%) on each of the second and third anniversaries of the Vesting Commencement Date. Vesting of the Units shall accelerate so that one hundred percent (100%) of the Units subject to the Award shall vest (i) in the event of a Change in Control Event and, with respect to Units, be converted in full to Shares, immediately prior to the specified effective date of the consummation of such Change in Control Event or (ii) upon termination of the Director’s Continuous Service as a result of death, Disability, or Retirement. Notwithstanding the foregoing, Shares or Units subject to an Award granted on or after January 17, 2012, shall vest on the Award Date. Conversion of the vested Units into Shares, however, will not occur until the Director’s Continuous Service terminates, or immediately prior to a Change in Control Event.

(b)

With respect to the Awards, notional dividends shall be credited at the same time, in the same form, and in equivalent amounts as dividends that are payable from time to time on the Common Stock. Any such notional dividends shall be valued as of the date on which they are credited and reallocated to acquire additional Units. Such additional Units shall vest in accordance with the vesting schedule set forth above, as if such Units had been issued on the date of such Awards.

1.1	“Board of Directors” means the Board of Directors of the Company.

1.2	“Change in Control” means the first to occur of any of the following events:

(a)	Any “person” (as the term is used in Sections 13 and 14(d)(2) of the Securities Exchange Act of 1934 (“Exchange Act”)) who becomes a beneficial owner (as that term is used in Section 13(d) of the Exchange Act), directly or indirectly, of 50 percent or more of the Company’s capital stock entitled to vote in the election of Directors; or

(b)

During any period of not more than twelve months, not including any period prior to the adoption of this Plan, individuals who, at the beginning of such period constitute the Board of Directors of the Company, and any new Director (other than a Director designated by a person who has entered into an agreement with the Company to effect a transaction described in clause (a) of this Article 1.2) whose election by the Board of Directors or nomination for election by the Company’s shareholders was approved by a vote of at least 75 percent of the Directors then still in office, who either were Directors at the beginning of the period or whose election or nomination for election was previously approved, cease for any reason to constitute at least a majority thereof.

1.3

“Committee” means the Compensation Committee of the Board of Directors to which the Board of Directors has given authority to manage and administer the Plan in accordance with the provisions of the Plan. After a Change in Control, the Committee shall cease to have any powers under the Plan and all powers previously vested in the Committee under the Plan will then be vested in the Third Party Fiduciary.

1.4	“Company” means Southwest Gas Corporation and any Successor Corporation.

1.5	“Director” means an outside, non-employee, member of the Board of Directors prior to a Change in Control.

1.6

“Disability” means either of the following circumstances as determined by the Committee in its sole discretion: (a) the Participant is unable to engage in any substantial gainful activity by reason of any medically determinable physical or mental impairment which can be expected to result in death or can be expected to last for a continuous period of not less than twelve months; or (b) the Participant is determined to be totally disabled by the Social Security Administration.

1.7	“Master Plan Document” means this legal instrument containing the provisions of the Plan.

1.8	“Participant” means an outside, non-employee Director who was elected or appointed to serve on the Board of Directors on or before January 20, 2003. As defined, former or current employees of the Company and Retired employees of the Company are excluded from participation in the Plan.

1.9	“Plan” means the Directors Retirement Plan evidenced by this Master Plan Document.

1.10	“Retiree” means a Retired Director who is eligible to receive benefits under the Plan.

1.11	“Retire”, “Retired” or “Retirement” means the termination of a Director’s service on the Board of Directors on one of the dates specified in Article 2.

1.12	“Successor Corporation” means any corporation or other legal entity which is the successor to Southwest Gas Corporation, whether resulting from merger, reorganization or transfer of substantially all of the assets of Southwest Gas Corporation, regardless of whether such entity shall expressly agree to continue the Plan.

1.13	“Third Party Fiduciary” means an independent third party selected by the Committee to take over the administration of the Plan upon and after a Change in Control and to determine appeals of claims denied under the Plan before and after a Change in Control pursuant to a Third Party Fiduciary Services Agreement.

1.14	“Third Party Fiduciary Services Agreement” means the agreement with the Third Party Fiduciary to perform services with respect to the Plan.

1.15	“Trust Agreement” means an agreement establishing a “grantor trust” of which the Company is the grantor, within the meaning of subpart E, part I, subchapter J, chapter 1, subtitle A of the IRC.

1.16	“Trust Fund or Funds” means the assets of every kind and description held under any Trust Agreement forming a part of the Plan.

1.17	“Trustee” means any person or entity selected by the Company to act as Trustee under any Trust Agreement at any time of reference.

1.18	“Years of Service” means the length of time, in discrete twelve-month periods, a Participant has served on the Board of Directors.

2.1	Retirement Benefits Each Participant is eligible to Retire and receive a benefit under this Plan beginning on one of the following dates, provided he qualifies:

(a)	“Normal Retirement Date,” which is the first day of the month following the month in which the Participant reaches age 65, provided he has at least ten Years of Service.

(b)	“Mandatory Retirement Date,” which is the first day of the month following the month in which the Participant reaches age 72.

(c)	“Postponed Retirement Date,” which is the first day of the month following the month in which the Participant terminates service on the Board of Directors, provided he has at least ten Years of Service and provided that such date is after the Normal Retirement Date and before the Mandatory Retirement Date.

(d)	“Disability Retirement Date,” which is the first day of the month following the month in which the Participant’s Disability began, as determined by the Committee.

2.2	Early Retirement A Participant is eligible to elect “Early Retirement” from the Board of Directors prior to age 65 provided he has at least ten Years of Service. The Participant electing Early Retirement will be eligible to receive benefits pursuant to Section 3.3.

2.3	Change in Control Notwithstanding the foregoing and upon the occurrence of a Change in Control, a Participant will be deemed Retired and receive the Normal Retirement Benefit beginning the first day of the month following such an event, provided he has at least five Years of Service at such time.

3.1	Normal Retirement Benefit The annual benefit payable under the Plan will be the amount of the Participant’s annual retainer fee on his Normal Retirement Date and will be paid for life as provided in Article 4.

3.2	Mandatory Retirement Benefit The annual benefit payable under the Plan will be the amount of the Participant’s annual retainer fee on his Mandatory Retirement Date and will be paid for life as provided in Article 4.

3.3	Early Retirement Benefit The annual benefit payable for Early Retirement under the Plan will be the amount of the Participant’s annual retainer fee on his Early Retirement date and will be paid for life commencing when the Participant reaches age 65 as provided in Article 4.

3.4	Postponed Retirement Benefit The annual benefit payable at a Postponed Retirement Date under the Plan will be the amount of the Participant’s annual retainer fee on the date of his postponed retirement and will be paid for life as provided in Article 4.

3.5	Disability Retirement Benefit The annual benefit payable at a Disability Retirement Date under the Plan will be the amount of the Participant’s annual retainer fee on the date of the Disability and will be paid for life as provided in Article 4.

3.6	Discretionary Benefits The Board of Directors may, at its sole discretion, grant to an eligible Participant an increased benefit of $1,000 per year for life for each ten-year period of service beyond the minimum qualifying service period of ten years.

4.1	Timing of Payments One-quarter of the benefit determined in accordance with Article 3 will be payable on the first day of each calendar quarter. The initial benefit payment will be paid within 30 days after a Participant’s Retirement, and will be prorated for a partial calendar quarter if the Retirement date is not on the first day of a calendar quarter.

4.2	Cessation of Benefits Benefit payments will cease on the first day of the calendar quarter following the Retiree’s death.

5.1	Death No benefits are payable under this Plan in the event of death.

6.1	Payment Obligation Amounts payable to a Participant shall be paid exclusively from the general assets of the Company or from the assets of a grantor trust within the meaning of subpart E, part I, subchapter J, chapter 1, subtitle A of the Code, established for use in funding executive compensation arrangements and commonly known as a “rabbi trust.”

6.2	Limitation on Payment Obligations The Company shall have no obligation under the Plan to a Participant, except as provided in this Plan.

6.3	Furnishing Information The Participant shall cooperate in furnishing all information requested by the Company to facilitate the payment of his benefit.

6.4

Unsecured General Creditor Participants and their heirs, successors, and assigns shall have no legal or equitable rights, claims, or interest in any specific property or assets of the Company. No assets of the Company shall be held under any trust, or held in any way as collateral security for the fulfilling of the obligations of the Company under the Plan. Any and all of the Company assets shall be, and remain, the general unpledged, unrestricted assets of the Company. The Company obligation under the Plan shall be merely that of an unfunded and unsecured promise of the Company to pay money in the future, and the rights of the Participants shall be no greater than those of unsecured general creditors. It is the intention of the Company that this Plan (and the Trust Funds described in Article 7) be unfunded for purposes of the Code.

6.5	Withholding There shall be deducted from each payment made under the Plan or other compensation payable to the Participant all taxes which are required to be withheld by the Company in respect to such payment under this Plan. The Company shall have the right to reduce any payment (or other compensation) by the amount of cash sufficient to provide the payment amount of said taxes.

6.6	Continued Tenure The Company is without power to lawfully assure a Participant continued tenure as a Director, and nothing herein constitutes a contract of continuing Directorship between the Company and the Participant.

7.1

Trusts The Company may maintain one or more Trust Funds to finance all or a portion of the benefits under the Plan by entering into one or more Trust Agreements. Any Trust Agreement is designated as, and shall constitute, a part of the Plan, and all rights which may accrue to any person under the Plan shall be subject to all the terms and provisions of such Trust Agreement. A Trustee shall be appointed by the Committee or the Board of Directors and shall have such powers as provided in the Trust Agreement. The Committee or the Board of Directors may modify any Trust Agreement, in accordance with its terms, to accomplish the purposes of the Plan and appoint a successor Trustee under the provisions of such Trust Agreement. By entering into such Trust Agreement, the Committee or the Board of Directors may vest in the Trustee, or in one or more investment managers (as defined in ERISA), the power to manage and control the Trust Fund. Committee authority under the provisions of this Article 7.1 will cease upon the occurrence of a Change in Control.

8.1

Plan Amendment To the extent permitted by the IRC and related regulations, the Board of Directors may, at any time, and without notice, amend or modify the Plan in whole or in part; provided, however, that: (a) no amendment or modification shall be effective to decrease or restrict (i) the benefits the Participant qualifies for under the provisions of the Plan, or (ii) benefit payments to Participants once such payments have commenced; and (b) effective January 1, 2005, no amendment or modification of this Article 8, Article 10, or Article 11 of the Plan shall be effective except to the extent both the Committee and the Board of Directors deems necessary to comply with applicable law.

8.2	Plan Termination The Board of Directors shall not terminate the Plan until all benefits have been paid in full to the Participants under the provisions of the Plan.

8.3

Bankruptcy To the extent permitted under Code Section 409A and its related Treasury regulations, the Board of Directors shall have the authority, in its sole discretion, to terminate the Plan and distribute each Participant’s benefits to the Participant within twelve months of a corporate dissolution taxed under Section 331 of the Code or with the approval of a bankruptcy court pursuant to 11 U.S.C. §503(b)(1)(a). The total accelerated distribution under this Article 8.3 must be included in a Participant’s gross income in the latest of:

(a)	The calendar year in which the Plan is terminated;

(b)	The calendar year in which the Participant’s benefits are no longer subject to a substantial risk of forfeiture; or

(c)	The calendar year in which distribution of the Participant’s benefits is administratively practicable.

9.1	No Assignment To the maximum extent permitted by law, no interest or benefit under the Plan shall be assignable or subject in any manner to alienation, sale, transfer, claims of creditors, pledge, attachment, or encumbrances of any kind.

10.1

Committee Duties Except as otherwise provided in this Article 10, and subject to Article 11, the general administration of the Plan, as well as construction and interpretation thereof, shall be vested in the Committee. Specifically, the Committee shall have the discretion and authority to: (a) make, amend, interpret, and enforce all appropriate rules and regulations for the administration of the Plan; and (b) decide or resolve any and all questions including interpretations of the Plan. Any individual serving on the Committee who is a Participant shall not vote or act on any matter relating solely to himself or herself. The number of members of the Committee shall be established by, and the members shall be appointed from time to time by, and shall serve at the pleasure of, the Board of Directors. Members of the Committee may be Participants under the Plan.

10.2

Administration after a Change in Control Upon and after a Change in Control, the administration of the Plan shall be vested in a Third Party Fiduciary, as provided for herein and pursuant to the terms of a Third Party Fiduciary Services Agreement. Any Third Party Fiduciary Services Agreement is designated as, and shall constitute, a part of the Plan. The Third Party Fiduciary shall also have the discretion and authority to: (a) make, amend, interpret, and enforce all appropriate rules and regulations for the administration of the Plan; and (b) decide or resolve any and all questions including interpretation of the Plan and the Trust Agreement. Except as otherwise provided for in any Trust Agreement, the Third Party Fiduciary shall have no power to direct the investment of Plan or Trust Funds or select any investment manager or custodial firm for the Plan or Trust Agreement. The Company shall pay all reasonable administrative expenses and fees of the Third Party Fiduciary when it acts as the administrator of the Plan or pursuant to Article 11. The Third Party Fiduciary may not be terminated by the Company without the consent of at least 50 percent of the Participants in the Plan.

10.3	Agents In the administration of the Plan, the Committee or the Third Party Fiduciary, as the case may be, may from time to time employ such agents, consultants, advisors, and managers as it deems necessary or useful in carrying out its duties as it sees fit (including acting through a duly authorized representative) and may from to time to time consult with counsel to the Company.

10.4

Binding Effect of Decisions The decision or action of the Committee or the Third Party Fiduciary, as the case may be, with respect to any question arising out of or in connection with the administration, interpretation, and application of the Plan (and the Trust Agreement to the extent provided for in Article 10.2) and the rules and regulations promulgated hereunder shall be final and conclusive and binding upon all persons having any interest in the Plan.

10.5

Indemnity by Company The Company shall indemnify and save harmless each member of the Committee, the Third Party Fiduciary, and any employee of the Company to whom the duties of the Committee may be delegated against any and all claims, losses, damages, expenses, and liabilities arising from any action or failure to act with respect to the Plan, except in the case of fraud, gross negligence, or willful misconduct by the Committee, any of its members, the Third Party Fiduciary, or any such employee.

10.6

Cooperation – Providing Information To enable the Committee and the Third Party Fiduciary to perform their functions, the Company shall supply full and timely information to the Committee and the Third Party Fiduciary, as the case may be, on all matters relating to the compensation of all Participants, their Retirement, death or other cause for termination of service, and such other pertinent facts as the Committee or the Third Party Fiduciary may require.

11.1	Presentation of Claims Any Participant (such Participant being referred to below as a “Claimant”) may deliver to the Committee a written claim for determination with respect to benefits available to such Claimant from the Plan. The claim must state with particularity the determination desired by the Claimant.

11.2	Notification of Decision The Committee shall consider a claim and notify the Claimant within 90 calendar days after receipt of a claim in writing:

(a)	That the Claimant’s requested determination has been made, and that the claim has been allowed in full; or

(b)

That the Committee has reached a conclusion contrary, in whole or in part, to the Claimant’s requested determination, and such notice must set forth in a manner calculated to be understood by the Claimant: (i) the specific reason(s) for the denial of the claim, or any part thereof; (ii) the specific reference(s) to pertinent provisions of the Plan upon which the denial was based; (iii) a description of any additional material or information necessary for the Claimant to perfect the claim, and an explanation of why such material or information is necessary; and (iv) an explanation of the claim review procedure set forth in Article 11.3.

11.3

Review of Denied Claim Within 60 days after receiving a notice from the Committee that a claim has been denied, in whole or in part, a Claimant (or the Claimant’s duly authorized representative) may file with the Third Party Fiduciary a written request for a review of the denial of the claim. Thereafter, the Claimant (or the Claimant’s duly authorized representative) may review pertinent documents, submit written comments or other documents, and request a hearing, which the Third Party Fiduciary, in its sole discretion, may grant.

11.4

Decision on Review The Third Party Fiduciary shall render its decision on review promptly, and not later than 60 days after the filing of a written request for review of a denial, unless a hearing is held or other special circumstances require additional time, in which case the Third Party Fiduciary’s decision must be rendered within 120 calendar days after such date. Such decision must be written in a manner calculated to be understood by the Claimant, and it must contain: (a) the specific reason(s) for the decision; (b) the specific reference(s) to the pertinent Plan provisions upon which the decision was based; and (c) such other matters as the Third Party Fiduciary deems relevant.

11.5	Legal Action A Claimant’s compliance with the foregoing provisions of this Article 11 is a mandatory prerequisite to a Claimant’s right to commence any legal action with respect to any claim for benefits under the Plan.

12.1	Recusal No Director will participate in an action of the Committee or the Board of Directors on a matter that solely applies to that Director. Such matters will be determined by a majority of the rest of the Committee or the Board of Directors.

12.2	Providing Plan Details Each Participant will receive a copy of this Plan, and the Committee will make available for any Participant’s inspection a copy of the rules and regulations the Committee uses in administering the Plan.

12.3	Governing Law Except to the extent federal law applies, the Plan shall be governed by, and construed under, the laws of the State of Nevada.

12.4	Assignment The Plan shall be binding upon the Company and any of its successors and assigns, and upon a Participant and their assigns, heirs, executors, and administrators.

12.5	Gender and Number Masculine pronouns wherever used shall include feminine pronouns and when the context dictates, the singular shall include the plural.

12.6	Headings Headings in this Master Plan Document are inserted for convenience of reference only. Any conflict between such headings and the text shall be resolved in favor of the text.

12.7	Severability In case any provision of the Plan shall be held illegal or invalid for any reason, said illegality or invalidity shall not affect the remaining parts hereof, but the Plan shall be construed and enforced as if such illegal and invalid provisions had never been inserted herein.

12.8	Notices Any notice given under the Plan shall be in writing and shall be mailed or delivered to:

1.1	“Account Balances” means a Participant's individual fund comprised of Deferrals and interest earnings credited thereon up to the applicable Benefit Distribution Date.

1.2	“Beneficiary” means the person, persons, entity or entities designated by the Participant to receive any benefits under the Plan upon the death of a Participant. A participant may designate primary and contingent Beneficiaries.

1.3	“Benefit Account Balances” shall have the meaning set forth in Article 5.1.

1.4	“Benefit Distribution Date” means the date benefits under the Plan are first paid to a Participant, or because of his death, to his Beneficiary, which will occur within 90 days of notification to the Company of the event that gives rise to such distribution.

1.5	“Board Fees” means the annual retainer, meeting and committee fees received by a Director for serving on the Board of Directors and its committees.

1.6	“Board of Directors” means the Board of Directors of the Company.

(a)	Any “person” (as the term is used in Section 13 and 14(d)(2) of the Securities Exchange Act of 1934 (“Exchange Act”)) who becomes a beneficial owner (as that term is used in Section 13(d) of the Exchange Act), directly or indirectly, of 50 percent or more of the Company’s capital stock entitled to vote in the election of Directors; or

(b)

During any period of not more than twelve months, not including any period prior to the adoption of this Plan, individuals who, at the beginning of such period constitute the Board of Directors of the Company, and any new Director (other than a Director designated by a person who has entered into an agreement with the Company to effect a transaction described in clause (a) of this Article 1.7) whose election by the Board of Directors or nomination for election by the Company’s shareholders was approved by a vote of at least 75 percent of the Directors then still in office, who either were Directors at the beginning of the period or whose election or nomination for election was previously approved, cease for any reason to constitute at least a majority thereof.

1.8	“Committee” means the administrative committee appointed by the Board of Directors to manage and administer the Plan in accordance with the provisions of the Plan. After a Change in Control, the Committee shall cease to have any powers under the Plan and all powers previously vested in the Committee under the Plan will then be vested in the Third Party Fiduciary.

1.9	“Company” means Southwest Gas Corporation and any Successor Corporation.

1.10	“Deferral(s)” means the amount of Board Fees earned and deferred in accordance with the provisions of the Plan.

1.11	“Director” means an outside, non-employee member of the Board of Directors prior to a Change in Control.

1.12	“Deferral Election Form” means the form of written agreement specifying deferral elections and a payout option which is completed and executed by the Participant and submitted to the Company in a timely manner.

1.13

“Disability” means either of the following circumstances, as determined by the Committee in its sole discretion: (a) the Participant is unable to engage in any substantial gainful activity by reason of any medically determinable physical or mental impairment which can be expected to result in death or can be expected to last for a continuous period of not less than twelve months; or (b) the Participant is determined to be totally disabled by the Social Security Administration.

1.14	“Master Plan Document” means this legal instrument containing the provisions of the Plan.

1.15

“Moody's Rate” means Moody's Seasoned Corporate Bond Rate which is an economic indicator consisting of an arithmetic average of yields of representative bonds (industrial and AAA, AA and A rated public utilities) as of January 1 prior to each Plan Year as published by Moody's Investors Service, Inc. (or any successor thereto), or, if such index is no longer published, a substantially similar index selected by the Board of Directors.

1.16	“Moody's Composite Rate” means the average of the Moody's Rate on January 1 for the five years prior to the Participant’s applicable Benefit Distribution Date.

1.17	“Participant” means any Director who executes a Plan Agreement or Deferral Election Form.

1.18	“Plan” means the Directors Deferral Plan of the Company evidenced by this Master Plan Document.

1.19	“Plan Agreement” means the form of written agreement which is entered into by and between the Company and a Participant.

1.20	“Plan Year” means the annual period beginning on March 15 of each calendar year and ending on March 14 of the next following year.

1.21	“Retire” or “Retirement” means the cessation of service on the Board of Directors of the Company after attaining five Years of Service, other than by death, Disability or Termination of Service.

1.22	“Subsidiary” means any corporation, partnership, or other organization which is at least 50 percent owned by the Company or a Subsidiary of the Company.

1.23	“Successor Corporation” means any corporation or other legal entity which is the successor to Southwest Gas Corporation, whether resulting from merger, reorganization or transfer of substantially all of the assets of Southwest Gas Corporation, regardless of whether such entity shall expressly agree to continue the Plan.

1.24	“Terminates Service” or “Termination of Service” means a Participant’s voluntary or involuntary cessation of service on the Board of Directors of the Company, for any reason except Retirement, Disability or death.

1.25	“Third Party Fiduciary” means an independent third party selected by the Committee to take over the administration of the Plan upon and after a Change in Control and to determine appeals of claims denied under the Plan before and after a Change in Control pursuant to a Third Party Fiduciary Services Agreement.

1.26	“Third Party Fiduciary Services Agreement” means the agreement with the Third Party Fiduciary to perform services with respect to the Plan.

1.27	“Trust Agreement” means an agreement establishing a “grantor trust” of which the Company is the grantor, within the meaning of subpart E, part I, subchapter J, chapter 1, subtitle A of the IRC.

1.28	“Trust Fund or Funds” means the assets of every kind and description held under any Trust Agreement forming a part of the Plan.

1.29	“Trustee” means any person or entity selected by the Company to act as Trustee under any Trust Agreement at any time of reference.

1.30	“Unforeseeable Emergency” means an unforeseeable emergency as defined in the Code and related Treasury regulations.

1.31	"Years of Service" means the length of time, in discrete twelve month periods, a Participant has served on the Board of Directors.

2.1	Eligibility A Director shall become eligible to participate in the Plan as of the effective date of his election as a Director, unless the Board of Directors determines at that time that such Director will not be eligible to participate in the Plan.

2.2

Commencement of Participation Once eligible to participate in the Plan, a Director must complete, execute and return to the Company a Plan Agreement in order to commence participation in the Plan. Continued participation in the Plan is subject to compliance with any further conditions as may be established by the Committee. Notwithstanding the foregoing and upon the occurrence of a Change in Control, no additional conditions regarding continued participation in the plan may be established by the Committee or any Successor Corporation.

3.1	Deferrals A Participant may defer up to 100 percent of his Board Fees received during a Plan Year; provided that such Deferral exceeds $2,000 per Plan Year. A Participant's Deferral election will be exercised at the time Board Fees are paid.

3.2

Benefit Payout Periods; Irrevocable Elections A Participant shall elect the period over which the amounts deferred under such election will be distributed to him commencing at the applicable Benefit Distribution Date. A Participant’s Account Balances shall be distributed in the form of substantially-equal installment payments over a period of 60, 120, 180 or 240 months, as elected by the Participant in accordance with this Article 3.2. Only one payout option is permitted for each Plan Year. However, a Participant is free to choose any available payout option for each subsequent Plan Year. If a Participant fails to make a valid election as to the period over which his Deferrals for a particular Plan Year will be distributed, the default distribution period for such Deferrals shall be 240 months. Payout elections are irrevocable once made.

3.3	Deadline for Deferral Elections By December 31st of each calendar year, a Participant must submit to the Company his completed and executed Deferral Election Form for the upcoming Plan Year. If a Participant fails to timely submit his Deferral Election Form, he will not be permitted to defer any of his Board Fees during the upcoming Plan Year.

3.4

Deferral Elections by New Participants When a Director first becomes eligible to participate in the Plan, initial Deferral elections will be permitted with respect to services performed after the elections, as long as such elections are made within 30 days after the date on which the Director became eligible to participate in the Plan. Such Participant must submit his Plan Agreement to the Company, in writing, at the time he elects to become a Participant in the Plan. Thereafter, in the event a Director becomes a Participant in the Plan, such Participant may defer Board Fees only in accordance with Article 3.2.

3.5

Ineffective Elections If there shall be a final determination by the Internal Revenue Service or a court of competent jurisdiction that the election by a Participant to defer the payment of any amount in accordance with the terms of this Plan was not effective to defer the taxation of such amount, then the Participant shall be entitled to receive a distribution of the amount determined to be taxable and the Participant’s Account Balances shall be reduced accordingly.

4.1	Interest Rate A Participant's Account Balances at the start of a Plan Year and any Deferrals made during a Plan Year will earn interest annually at 150 percent of the Moody's Rate. Interest will be credited to a Participant's accounts for Deferrals made during the Plan Year, as if all Deferrals were made on the first day of the Plan Year.

4.2	Interest Prior to Benefit Distribution Date A Participant's Account Balance will earn interest under the provisions of Article 4.1 until the applicable Benefit Distribution Date.

4.3	Interest Rate for Benefit Payment Calculation The interest rate used to calculate the amount that will be credited to Participant's Account Balances, to determine his Benefit Account Balances under the provisions of Article 5.1, will be 150 percent of the Moody's Composite Rate.

5.1

Benefit Account Balances A Participant’s Account Balances, at the applicable Benefit Distribution Date, will be credited with an amount equal to the interest such balances would have earned assuming distribution in equal monthly installments over the specific benefit payment periods, at a specified interest rate, thereby creating Benefit Account Balances. The Benefit Account Balances will then be paid to the Participant in equal monthly installments over the benefit payment periods previously elected by the Participant or specified by the Plan.

6.1	Pre-Retirement Death of Participant Notwithstanding any elections made pursuant to Article 3.2, if a Participant dies while he is a member of the Board of Directors, his Account Balances will be paid to his Beneficiary in equal monthly installments over the 180 month survivor benefit payment period commencing as of the applicable Benefit Distribution Date.

6.2	Interest on Benefit Payments The interest rate used to determine the amount

7.1	Post-Retirement Death of Participant If a Participant dies after the commencement of benefit payments under this Plan but prior to such benefits having been paid in full, the Participant's benefit payments will continue to be paid to the Participant's Beneficiary through the end of the benefit payment periods previously elected by the Participant.

8.1

Payment Following Disability Notwithstanding any elections made pursuant to Article 3.2, if a Participant becomes Disabled within the first five Years of Service with the Company, he will receive his Benefit Account Balances in a lump sum payment on the applicable Benefit Distribution Date. If a Participant becomes Disabled after having completed five or more Years of Service with the Company, the Benefit Account Balances will be paid consistent with the benefit payout periods previously elected.

8.2	Interest on Benefit Payments If a Participant qualifies to receive benefits due to a Disability, the interest rate used to calculate the amount that will be credited to Participant's Account Balances, to determine his Benefit Account Balances under the provisions of Article 5.1, will be 150 percent of the Moody's Composite Rate.

9.1

Designation of Beneficiaries A Participant shall have the right to designate any Beneficiary to whom benefits under this Plan shall be paid in the event of the Participant's death prior to the total distribution of his Benefit Account Balances under the Plan. If the Participant is married and greater than 50 percent of the Benefit Account Balances is designated to a Beneficiary other than the Participant's spouse, such Beneficiary designation must be consented to by the Participant's spouse. Each Beneficiary designation must be in written form prescribed by the Company and will be effective only when filed with the Company during the Participant's lifetime. The Company shall acknowledge, in writing, receipt of each Beneficiary designation form.

9.2	Changing Beneficiary Designation A Participant shall have the right to change the Beneficiary designation, subject to spousal consent under the provisions of Article 10.1, without the consent of any designated Beneficiary by filing a new Beneficiary designation with the Company. The filing of a new Beneficiary designation form will cancel all Beneficiary designations previously filed.

9.3	Discharge of Company Obligation Both the Company and the Committee shall be entitled to rely on the Beneficiary designation last filed by the Participant prior to his death. Any payment made in accordance with such designation shall fully discharge the Company and the Committee from all further obligations with respect to the Participant’s rights in the Plan.

9.4

Minor or Incompetent Beneficiaries If a Beneficiary entitled to receive benefits under the Plan is a minor or a person declared incompetent, the Committee may direct payment of such benefits to the guardian or legal representative of such minor or incompetent person. The Committee may require proof of incompetency, minority or guardianship as it may deem appropriate prior to distribution of any Plan benefits. Such distribution shall completely discharge the Committee and the Company from all liability with respect to such payments.

9.5	Effect of No Beneficiary Designation If no Beneficiary designation is in effect at the time of the Participant's death, or if the named Beneficiary predeceased the Participant, then the Beneficiary shall be: (a) the surviving spouse; (b) if there is no surviving spouse, then his issue per stirpes; or (c) if no surviving spouse or issue, then his estate.

9.6	Beneficiary’s Beneficiaries If a Participant’s Beneficiary receiving benefit payments under the provisions of the Plan dies prior to the completion of the benefit payment periods, the Participant’s benefit payments will continue to be paid through the end of the benefit payment periods previously elected by the Participant, to the Beneficiary’s Beneficiary, if any, or the applicable estate.

10.1	Payment Obligation Amounts payable to a Participant or Beneficiary shall be paid exclusively from the general assets of the Company or from the assets of a grantor trust within the meaning of subpart E, part I, subchapter J, chapter 1, subtitle A of the Code, established for use in funding executive compensation arrangements and commonly known as a “rabbi trust.”

10.2	Limitation or Payment Obligation The Company shall have no obligation under the Plan to a Participant or a Participant's Beneficiary, except as provided in this Master Plan Document.

10.3	Furnishing Information The Participant or Beneficiary shall cooperate in furnishing all information requested by the Company to facilitate the payment of his Benefit Account Balances.

10.4	Unsecured General Creditor Participants and their Beneficiaries, heirs, successors, and assigns shall have no legal or equitable rights, claims, or interest

10.5	Withholding There shall be deducted from each payment made under the Plan or other compensation payable to the Participant (or Beneficiary) all taxes which are required to be withheld by the Company in respect to such payment under this Plan. The Company shall have the right to reduce any payment (or other compensation) by the amount of cash sufficient to provide the amount of said taxes.

10.6	Continued Tenure The Company is without power to lawfully assure a Participant continued tenure as a Director, and nothing herein constitutes a contract of continuing Directorship between the Company and the Participant.

10.7

Trusts The Company may maintain one or more Trust Funds to finance all or a portion of the benefits under the Plan by entering into one or more Trust Agreements. Any Trust Agreement is designated as, and shall constitute, a part of the Plan, and all rights which may accrue to any person under the Plan shall be subject to all the terms and provisions of such Trust Agreement. A Trustee shall be appointed by the Committee or the Board of Directors and shall have such powers as provided in the Trust Agreement. The Committee or the Board of Directors may modify any Trust Agreement, in accordance with its terms, to accomplish the purposes of the Plan and appoint a successor Trustee under the provisions of such Trust Agreement. By entering into such Trust Agreement, the Committee or the Board of Directors may vest in the Trustee, or in one or more investment managers (as defined in ERISA) the power to manage and control the Trust Fund. Committee authority under the provisions of this Article 10.7 will cease upon the occurrence of a Change in Control.

10.8	No Assignment To the maximum extent permitted by law, no interest or benefit under the Plan shall be assignable or subject in any manner to alienation, sale, transfer, claims of creditors, pledge, attachment or encumbrances of any kind.

11.1

Plan Amendment To the extent permitted by the IRC and related regulations, the Board of Directors may at any time, and without notice, amend or modify the Plan in whole or in part; provided, however, that (a) no amendment or modification shall be effective to decrease or restrict (i) the amount of interest to be credited to a Participant’s Account Balances under the provisions of the Plan, (ii) the benefits the Participant qualifies for or may elect to receive under the provisions of the Plan, or (iii) benefit payments to Participants or Beneficiaries once such payments have commenced, and (b) effective January 1, 2005, no amendment or modification of this Article 11, Article 12, or Article 13 of the Plan shall be effective except to the extent both the Committee and the Board of Directors deems necessary to comply with applicable law.

11.2	Plan Termination The Board of Directors shall not terminate the Plan until all benefits owed to the Participants and Beneficiaries have been paid in full.

11.3

Bankruptcy To the extent permitted under code Section 409A and related Treasury regulations, the Board of Directors shall have the authority, in its sole discretion, to terminate the Plan and distribute each Participant’s Account Balances to the Participant or, if applicable, his or her Beneficiary within twelve months of a corporate dissolution taxed under Section 331 of the Code or with the approval of a bankruptcy court pursuant to 11 U.S.C. § 503(b)(1)(a). The total accelerated distribution under this Article 11.3 must be included in a Participant’s gross income in the latest of:

(a)	The calendar year in which the Plan is terminated;

(b)	The calendar year in which the Participant’s Account Balances are no longer subject to a substantial risk of forfeiture; or

(c)	The calendar year in which distribution of the Participant’s Account Balances is administratively practicable.

11.4

Partial Plan Termination The Board of Directors may partially terminate the Plan by instructing the Company not to accept any additional Deferral commitments. In the event of a partial termination, the remaining provisions of the Plan shall continue to operate and be effective for all Participants in the Plan, as of the date of such partial termination. Any such instructions and any reinstatement of the Plan shall be implemented in accordance with the IRC and related regulations.

12.1

Committee Duties Except as otherwise provided in this Article 12, and subject to Article 13, the general administration of the Plan, as well as construction and interpretation thereof, shall be vested in the Committee. Members of the Committee may be Participants under the Plan. Specifically, the Committee shall have the discretion and authority to: (a) make, amend, interpret, and enforce all appropriate rules and regulations for the administration of the Plan; and (b) decide or resolve any and all questions including interpretations of the Plan. Any individual serving on the Committee who is a Participant shall not vote or act on any matter relating solely to himself or herself. The number of members of the Committee shall be established by, and the members shall be appointed from time to time by, and shall serve at the pleasure of, the Board of Directors.

12.2

Administration after a Change in Control Upon and after a Change in Control, the administration of the Plan shall be vested in a Third Party Fiduciary, as provided for herein and pursuant to the terms of a Third Party Fiduciary Services Agreement. Any Third Party Fiduciary Services Agreement is designated as, and shall constitute, a part of the Plan. The Third Party Fiduciary shall also have the discretion and authority to: (a) make, amend, interpret, and enforce all appropriate rules and regulations for the administration of the Plan; and (b) decide or resolve any and all questions including interpretation of the Plan and the Trust Agreement. Except as otherwise provided for in any Trust Agreement, the Third Party Fiduciary shall have no power to direct the investment of Plan or Trust Funds or select any investment manager or custodial firm for the Plan or Trust Agreement. The Company shall pay all reasonable administrative expenses and fees of the Third Party Fiduciary when it acts as the administrator of the Plan or pursuant to

12.3	Agents In the administration of the Plan, the Committee or the Third Party Fiduciary, as the case may be, may from time to time employ such agents, consultants, advisors, and managers as it deems necessary or useful in carrying out its duties as it sees fit (including acting through a duly authorized representative) and may from to time to time consult with counsel to the Company.

12.4

Binding Effects of Decisions The decision or action of the Committee or the Third Party Fiduciary, as the case may be, with respect to any question arising out of or in connection with the administration, interpretation, and application of the Plan (and the Trust Agreement to the extent provided for in Article 12.2) and the rules and regulations promulgated hereunder shall be final and conclusive and binding upon all persons or entities having any interest in the Plan.

12.5

Indemnity by Company The Company shall indemnify and save harmless each member of the Committee, the Third Party Fiduciary, and any employee of the Company to whom the duties of the Committee may be delegated against any and all claims, losses, damages, expenses, and liabilities arising from any action or failure to act with respect to the Plan, except in the case of fraud, gross negligence, or willful misconduct by the Committee, any of its members, the Third Party Fiduciary, or any such employee.

12.6

Cooperation – Providing Information To enable the Committee and the Third Party Fiduciary to perform their functions, the Company shall supply full and timely information to the Committee and the Third Party Fiduciary, as the case may be, on all matters relating to the compensation of all Participants, their Retirement, death or other cause for Termination of Service, and such other pertinent facts as the Committee or the Third Party Fiduciary may require.

12.7

Unforeseeable Emergencies In the event of an Unforeseeable Emergency, the Committee or the Third Party Fiduciary, as the case may be, may in its sole discretion, permit distribution to a Participant or Beneficiary from this Plan an amount no greater than the amount necessary to satisfy the Unforeseeable Emergency plus any taxes reasonably anticipated as a result of the distribution; or permit a Participant to cancel his or her Deferral election for the applicable Plan Year in accordance with applicable Treasury regulations without an accompanying distribution from his or her Account Balances. A Participant’s current Deferral election, if any, shall automatically terminate upon such Participant’s receipt of a withdrawal under this Article 12.7. To the extent such a Participant again becomes eligible to elect Deferrals in accordance with the terms of the Plan, any subsequent Deferral elections made by the Participant must be made in accordance with the provisions of Article 3.

13.1	Presentation of Claims Any Participant or Beneficiary of a deceased Participant (such Participant or Beneficiary being referred to below as a “Claimant”) may deliver to the Committee a written claim for determination with respect to benefits available to such Claimant from the Plan. The claim must state with particularity the determination desired by the Claimant.

13.2	Notification of Decision The Committee shall consider a claim and notify the Claimant within 90 calendar days after receipt of a claim in writing:

(a)	That the Claimant’s requested determination has been made, and that the claim has been allowed in full; or

(b)

That the Committee has reached a conclusion contrary, in whole or in part, to the Claimant’s requested determination, and such notice must set forth in a manner calculated to be understood by the Claimant: (i) the specific reason(s) for the denial of the claim, or any part thereof; (ii) the specific reference(s) to pertinent provisions of the Plan upon which the denial was based; (iii) a description of any additional material or information necessary for the Claimant to perfect the claim, and an explanation of why such material or information is necessary; and (iv) an explanation of the claim review procedure set forth in Article 13.3.

13.3

Review of a Denied Claim Within 60 days after receiving a notice from the Committee that a claim has been denied, in whole or in part, a Claimant (or the Claimant’s duly authorized representative) may file with the Third Party Fiduciary a written request for a review of the denial of the claim. Thereafter, the Claimant (or the Claimant’s duly authorized representative) may review pertinent documents, submit written comments or other documents, and request a hearing, which the Third Party Fiduciary, in its sole discretion, may grant.

13.4

Decision on Review The Third Party Fiduciary shall render its decision on review promptly, and not later than 60 days after the filing of a written request for review of a denial, unless a hearing is held or other special circumstances require additional time, in which case the Third Party Fiduciary’s decision must be rendered within 120 calendar days after such date. Such decision must be written in a manner calculated to be understood by the Claimant, and it must contain: (a) the specific reason(s) for the decision; (b) the specific reference(s) to the pertinent Plan provisions upon which the decision was based; and (c) such other matters as the Third Party Fiduciary deems relevant.

13.5	Legal Action A Claimant’s compliance with the foregoing provisions of this

14.1	Notices Any notice given under the Plan shall be in writing and shall be mailed or delivered to:

14.2	Assignment The Plan shall be binding upon the Company and any of its successors and assigns, and upon a Participant, a Participant's Beneficiary, and their assigns, heirs, executors and administrators.

14.3	Governing Law Except to the extent that federal law applies, the Plan shall be governed by and construed under the laws of the State of Nevada.

14.4	Headings Headings in this Master Plan Document are inserted for convenience of reference only. Any conflict between such headings and the text shall be resolved in favor of the text.

14.5	Gender and Number Masculine pronouns wherever used shall include feminine pronouns and when the context dictates, the singular shall include the plural.

14.6	Severability In case any provision of the Plan shall be held illegal or invalid for any reason, said illegality or invalidity shall not affect the remaining parts hereof, but the Plan shall be construed and enforced as if such illegal and invalid provisions had never been inserted herein.

ARTICLE I	DEFINITIONS    1

SECTION 1.1	Definitions    1

SECTION 1.2	Other Definitions and Provisions    3637

SECTION 1.3	Accounting Terms    37

SECTION 1.4	UCC and PPSA Terms    3738

SECTION 1.5	Rounding    38

SECTION 1.6	References to Agreement and Laws    38

SECTION 1.7	Times of Day    3839

SECTION 1.8	Letter of Credit Amounts    3839

SECTION 1.9	Guarantees/Earn-Outs    3839

SECTION 1.10	Alternative Currency Matters    3839

SECTION 1.11	Rates    39

ARTICLE II	REVOLVING CREDIT FACILITY    3940

SECTION 2.1	Revolving Credit Loans    3940

SECTION 2.2	Swingline Loans    3940

SECTION 2.3	Procedure for Advances of Revolving Credit Loans and Swingline Loans    41

SECTION 2.4	Repayment and Prepayment of Revolving Credit and Swingline Loans    42

SECTION 2.5	Permanent Reduction of the Revolving Credit Commitment    4344

SECTION 2.6	Termination of Revolving Credit Facility    4445

ARTICLE III	LETTER OF CREDIT FACILITY    4445

SECTION 3.1	L/C Facility    4445

SECTION 3.2	Procedure for Issuance of Letters of Credit    4546

SECTION 3.3	Commissions and Other Charges    46

SECTION 3.4	L/C Participations    4647

SECTION 3.5	Reimbursement Obligation of the Borrowers    4748

SECTION 3.6	Obligations Absolute    48

SECTION 3.7	Effect of Letter of Credit Application    4849

SECTION 3.8	Removal and Resignation of Issuing Lenders    4849

SECTION 3.9	Reporting of Letter of Credit Information and L/C Commitment    49

SECTION 3.10	Letters of Credit Issued for Subsidiaries    4950

ARTICLE IV	TERM LOAN FACILITY    4950

SECTION 4.1	Initial Term Loans    4950

SECTION 4.2	Procedure for Advance of Initial Term Loans    4950

SECTION 4.3	Repayment of Term Loans    5051

SECTION 4.4	Prepayments of Term Loans    5152

ARTICLE V	GENERAL LOAN PROVISIONS    5354

SECTION 5.1	Interest    5354

SECTION 5.2	Notice and Manner of Conversion or Continuation of Loans    5657

SECTION 5.3	Fees    5758

SECTION 5.4	Manner of Payment    5758

SECTION 5.5	Evidence of Indebtedness    5859

SECTION 5.6	Sharing of Payments by Lenders    5859

SECTION 5.7	Administrative Agent’s Clawback    5960

SECTION 5.8	Changed Circumstances    6061

SECTION 5.9	Indemnity    6364

SECTION 5.10	Increased Costs    6364

SECTION 5.11	Taxes    6465

SECTION 5.12	Mitigation Obligations; Replacement of Lenders    6869

SECTION 5.13	Incremental Loans    6970

SECTION 5.14	Cash Collateral    7172

SECTION 5.15	Defaulting Lenders    7273

SECTION 5.16	Centuri as Agent for the Borrowers    7475

ARTICLE VI	CONDITIONS OF CLOSING AND BORROWING    7475

SECTION 6.1	Conditions to Closing and Initial Extensions of Credit    7475

SECTION 6.2	Conditions to All Extensions of Credit    7880

ARTICLE VII	REPRESENTATIONS AND WARRANTIES OF THE CREDIT PARTIES    7980

SECTION 7.1	Organization; Power; Qualification    7980

SECTION 7.2	Ownership    7981

SECTION 7.3	Authorization; Enforceability    8081

SECTION 7.4	Compliance of Agreement, Loan Documents and Borrowing with Laws, Etc    8081

SECTION 7.5	Compliance with Law; Governmental Approvals    8081

SECTION 7.6	Tax Returns and Payments    8082

SECTION 7.7	Intellectual Property Matters    8182

SECTION 7.8	Environmental Matters    8182

SECTION 7.9	Employee Benefit Matters    8283

SECTION 7.10	Margin Stock    8384

SECTION 7.11	Government Regulation    8485

SECTION 7.12	Material Contracts    8485

SECTION 7.13	Employee Relations    8485

SECTION 7.14	Burdensome Provisions    8485

SECTION 7.15	Financial Statements    8485

SECTION 7.16	No Material Adverse Change    8486

SECTION 7.17	Solvency    8586

SECTION 7.18	Title to Properties    8586

SECTION 7.19	Litigation    8586

SECTION 7.20	Anti-Corruption Laws and Sanctions    8586

SECTION 7.21	Absence of Defaults    8587

SECTION 7.22	Senior Indebtedness Status    8687

SECTION 7.23	Disclosure    8687

SECTION 7.24	Insurance    8687

ARTICLE VIII	AFFIRMATIVE COVENANTS    8687

SECTION 8.1	Financial Statements and Budgets    8688

SECTION 8.2	Certificates; Other Reports    8889

SECTION 8.3	Notice of Litigation and Other Matters    9091

SECTION 8.4	Preservation of Corporate Existence and Related Matters    9192

SECTION 8.5	Maintenance of Property and Licenses    9192

SECTION 8.6	Insurance    9192

SECTION 8.7	Accounting Methods and Financial Records    9192

SECTION 8.8	Payment of Taxes and Other Obligations    9193

SECTION 8.9	Compliance with Laws and Approvals    9293

SECTION 8.10	Environmental Laws    9293

SECTION 8.11	Compliance with ERISA and Canadian Pension Laws    9293

SECTION 8.12	Compliance with Material Contracts    9294

SECTION 8.13	Visits and Inspections    9394

SECTION 8.14	Additional Subsidiaries and Collateral    9394

SECTION 8.15	Use of Proceeds    9596

SECTION 8.16	Corporate Governance    9596

SECTION 8.17	Further Assurances    9596

SECTION 8.18	Compliance with Anti-Corruption Laws; Beneficial Ownership Regulation, Anti-Money Laundering Laws and Sanctions    9596

SECTION 8.19	Post-Closing Matters    9597

ARTICLE IX	NEGATIVE COVENANTS    9597

SECTION 9.1	Indebtedness    9597

SECTION 9.2	Liens    9798

SECTION 9.3	Investments    98100

SECTION 9.4	Fundamental Changes    100101

SECTION 9.5	Asset Dispositions    100102

SECTION 9.6	Restricted Payments    101103

SECTION 9.7	Transactions with Affiliates    102103

SECTION 9.8	Accounting Changes; Organizational Documents    103104

SECTION 9.9	Payments and Modifications of Subordinated Indebtedness    103104

SECTION 9.10	No Further Negative Pledges; Restrictive Agreements    103105

SECTION 9.11	Nature of Business    104105

SECTION 9.12	Sale Leasebacks    104105

SECTION 9.13	Financial Covenants    104106

SECTION 9.14	Disposal of Subsidiary Interests    104106

ARTICLE X	DEFAULT AND REMEDIES    105106

SECTION 10.1	Events of Default    105106

SECTION 10.2	Remedies    107108

SECTION 10.3	Rights and Remedies Cumulative; Non-Waiver; etc    107109

SECTION 10.4	Crediting of Payments and Proceeds    108109

SECTION 10.5	Administrative Agent May File Proofs of Claim    110111

SECTION 10.6	Credit Bidding    110112

SECTION 10.7	Judgment Currency    111112

ARTICLE XI	THE ADMINISTRATIVE AGENT    111113

SECTION 11.1	Appointment and Authority    111113

SECTION 11.2	Rights as a Lender    112113

SECTION 11.3	Exculpatory Provisions    112114

SECTION 11.4	Reliance by the Administrative Agent    113114

SECTION 11.5	Delegation of Duties    113115

SECTION 11.6	Resignation of Administrative Agent    114115

SECTION 11.7	Non-Reliance on Administrative Agent and Other Lenders    115116

SECTION 11.8	No Other Duties, Etc    115116

SECTION 11.9	Collateral and Guaranty Matters    115116

SECTION 11.10	Secured Hedge Agreements and Secured Cash Management Agreements    116117

ARTICLE XII	MISCELLANEOUS    116118

SECTION 12.1	Notices    116118

SECTION 12.2	Amendments, Waivers and Consents    119120

SECTION 12.3	Expenses; Indemnity    121122

SECTION 12.4	Right of Setoff    123124

SECTION 12.5	Governing Law; Jurisdiction, Etc    123125

SECTION 12.6	Waiver of Jury Trial    124125

SECTION 12.7	Reversal of Payments    124126

SECTION 12.8	Injunctive Relief    124126

SECTION 12.9	Successors and Assigns; Participations    125126

SECTION 12.10	Treatment of Certain Information; Confidentiality    128130

SECTION 12.11	Performance of Duties    129131

SECTION 12.12	All Powers Coupled with Interest    129131

SECTION 12.13	Survival    129131

SECTION 12.14	Titles and Captions    130131

SECTION 12.15	Severability of Provisions    130131

SECTION 12.16	Counterparts; Integration; Effectiveness; Electronic Execution    130131

SECTION 12.17	Term of Agreement    130132

SECTION 12.18	USA PATRIOT Act; Anti-Money Laundering Laws    131132

SECTION 12.19	Independent Effect of Covenants    131132

SECTION 12.20	No Advisory or Fiduciary Responsibility    131132

SECTION 12.21	Inconsistencies with Other Documents    132133

SECTION 12.22	Acknowledgement and Consent to Bail-In of EEA Financial Institutions    132133

SECTION 12.23	Certain ERISA Matters    134

SECTION 12.24	Amendment and Restatement; No Novation    132134

(1)

Periods prior to 2018 depict revised Operating expenses and Operating income for the reclassification of non-service cost components of net periodic benefit costs in both the Company’s and Southwest’s Consolidated Statements of Income in the Annual Report to Shareholders due to the adoption of ASU 2017-07. Net income was not impacted. Refer to Note 11 - Pension and Other Postretirement Benefits in the notes to the Consolidated Financial Statements in this Annual Report to Shareholders for further information relating to the adoption of this update.

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(1)

Periods prior to 2018 depict revised Operations and maintenance expense and Operating income for the reclassification of non-service cost components of net periodic benefit costs in both the Company’s and Southwest’s Consolidated Statements of Income in the Annual Report to Shareholders due to the adoption of ASU 2017-07. Net income was not impacted. Refer to Note 11 - Pension and Other Postretirement Benefits in the notes to the Consolidated Financial Statements in this Annual Report to Shareholders for further information relating to the adoption of this update.

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•	Added 32,000 net new customers (1.6% growth rate) in 2018

•	Operating margin decreased $9 million between years, as $20 million of tax savings were returned to Arizona customers

•	Rate relief and customer growth, combined, provided $17 million in incremental margin in 2018

•	Pension cost increased nearly $8 million between years

•	Company-Owned Life Insurance (“COLI”) cash surrender values declined $13.5 million between years

•	Issued $300 million in 3.70% senior notes in March 2018

•	Record revenues of $1.5 billion were experienced in 2018, an increase of $276 million, or 22%, compared to 2017

•	Utility infrastructure services expenses increased $239 million, or 21%, compared to 2017

•	2018 results include a full year of Neuco, which was acquired in November 2017

•	Completed the acquisition of Linetec Services, LLC in November 2018

•	Issued 3,565,000 shares of common stock in an underwritten public offering in November 2018

•	Jane Lewis-Raymond and Leslie T. Thornton joined the Board of Directors in January 2019

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(1)	Moody’s debt ratings range from Aaa (highest rating possible) to C (lowest quality, usually in default). Moody’s applies an A rating to obligations which are considered upper-medium grade obligations with low credit risk. A numerical modifier of 1 (high end of the category) through 3 (low end of the category) is included with the A to indicate the approximate rank of a company within the range.

(2)

Standard & Poor’s (“S&P”) debt ratings range from AAA (highest rating possible) to D (obligation is in default). The S&P rating of BBB+ indicates the issuer of the debt is regarded as having an adequate capacity to pay interest and repay principal. The ratings from ‘AA’ to ‘CCC’ may be modified by the addition of a plus “+” or minus “-” sign to show relative standing within the major rating categories. The S&P outlook of “negative” was updated in November 2018 in consideration of an assumed cash flow impact from U.S. tax reform and growth in the utility infrastructure services segment.

(3)	Fitch debt ratings range from AAA (highest credit quality) to D (defaulted debt obligation). The Fitch rating of A indicates low default risk and a strong ability to pay financial commitments. The modifiers “+” or “-” may be appended to a rating to denote relative status within major rating categories.

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(1)	The number of securities granted for 2018 and 2017 includes 23,000 and 7,000 performance shares, respectively, the total of which was derived by assuming that target performance will be achieved during the relevant performance period.

•	A lease liability for the obligation to make lease payments, measured on a discounted basis; and

•	A right-of-use asset for the right to use, or control the use of, a specified asset for the lease term.

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To elect to use the “package”, which is a set of three practical expedients that must be elected as a package and applied consistently to all of the Company’s and Southwest’s leases. These include: not reassessing whether any expired or existing contracts are or contain leases; not reassessing the lease classification for expired or existing leases (that is, existing operating and capital leases in accordance with current lease guidance will in each case be classified as operating and finance leases, respectively, under the updated guidance); and not reassessing initial direct costs for any existing leases.

•	To elect to adopt the practical expedient to exclude all easements in place prior to January 1, 2019 from treatment under Topic 842. However, the Company and Southwest will evaluate any new easements entered into after the effective date of the standard to determine if the arrangements should be accounted for as leases.

•	To make an accounting policy election by asset class to include both the lease and non-lease components (as defined in the guidance) as a single component.

•	To make an accounting policy election to not apply Topic 842 to short-term leases, as permitted.

•	To not elect to use hindsight in determining the lease term and in assessing impairment of right-of-use assets.

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(a)	Includes various other revenues, and during the first six months of 2018, included $12.5 million as a reserve against revenue associated with a tax reform savings adjustment. During the third quarter of 2018, amounts previously recognized were reclassified to the various categories of revenue from contracts with customers when incorporated in tariff rates.

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(1)	Included in Deferred charges and other assets on the Consolidated Balance Sheets. Recovery period is greater than five years. (See Note 11 - Pension and Other Postretirement Benefits).

(2)

Asset balance is included in Deferred charges and other assets and Prepaid and other assets on the Consolidated Balance Sheets. Liability balance is included in Other current liabilities and Other deferred credits and other long-term liabilities on the Consolidated Balance Sheets. The actual amounts, when realized at settlement, become a component of purchased gas costs under Southwest’s PGA mechanisms. (For specific details, see Note 14 - Derivatives).

(3)	Balance recovered or refunded on an ongoing basis with interest.

(4)	Included in Prepaid and other current assets on the Consolidated Balance Sheets. Balance recovered or refunded on an ongoing basis.

(5)	Included in Deferred charges and other assets on the Consolidated Balance Sheets. Recovered over life of debt instruments.

(6)	Included in Other deferred credits and other long-term liabilities on the Consolidated Balance Sheets. Amortized over life of debt instruments.

(7)

The TCJA required a remeasurement and reduction of the net deferred income tax liability. The reduction (excess deferred taxes) became a regulatory liability with appropriate tax gross-up. The excess deferred taxes reduce rate base. The tax benefit will be returned to utility customers in accordance with regulatory requirements. Included in Other deferred credits and other long-term liabilities on the Consolidated Balance Sheets. This amount also includes a $2.9 million gross-up related to contributions in aid of construction.

(8)	Regulatory recovery occurs on a one-year lag basis through the labor loading process. Included in Prepaid and other current assets on the Consolidated Balance Sheets.

(9)	Margin tracking/decoupling mechanisms are alternative revenue programs and revenue associated with under-collections (for the difference between authorized margin levels and amounts billed to customers through rates currently) are recognized as revenue so long as recovery is expected to take place within 24 months. Included in Prepaid and other current assets on the Consolidated Balance Sheets.

(10)

The following tables detail the components of Other regulatory assets and liabilities. Other regulatory assets are included in either Prepaid and other current assets or Deferred charges and other assets on the Consolidated Balance Sheets (as indicated). Recovery periods vary. Other regulatory liabilities are included in either Other current liabilities or Other deferred credits and other long-term liabilities on the Consolidated Balance Sheets (as indicated).

a)	Included in Prepaid and other current assets on the Consolidated Balance Sheets. See Prepaid and other current assets in Note 1 - Background, Organization, and Summary of Significant Accounting Policies.

b)	Included in Deferred charges and other assets on the Consolidated Balance Sheets.

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c)	In 2018, approximately $4.5 million included in Prepaid and other current assets and $596,000 included in Deferred charges and other assets on the Consolidated Balance Sheets. In2017, $9.2 million included in Prepaid and other current assets and $527,000 included in Deferred charges and other assets on the Consolidated Balance Sheets.

d)

In 2018, $197,000 included in Prepaid and other current assets and $8.6 million included in Deferred charges and other assets on the Consolidated Balance Sheets. In 2017, $531,000 included in Prepaid and other current assets and $1.3 million included in Deferred charges and other assets on the Consolidated Balance Sheets. The balance in 2018 includes $6 million authorized as part of the recently concluded Nevada general rate case associated with self-insurance cost.

e)	Balance recovered or refunded on an ongoing basis, generally with interest.

a)	Included in Other current liabilities on the Consolidated Balance Sheets.

b)	In 2018, $(539,000) included in Other current liabilities and $(6.7) million included in Other deferred credits and other long-term liabilities on the Consolidated Balance Sheets. In 2017, $(6.6) million included in Other current liabilities and $(2.9) million included in Other deferred credits and other long-term liabilities on the Consolidated Balance Sheets.

c)	Included in Other deferred credits and other long-term liabilities on the Consolidated Balance Sheets.

d)	In 2018, $(810,000) included in Other current liabilities and $(9,000) included in Other deferred credits and other long-term liabilities on the Consolidated Balance Sheets. In 2017, approximately $(1.7) million included in Other current liabilities and $(9,000) included in Other deferred credits and other long-term liabilities on the Consolidated Balance Sheets.

e)	Balance recovered or refunded on an ongoing basis, generally with interest.

f)	In 2018, included in Prepaid and other current assets on the Consolidated Balance Sheets. In 2017, included in Other current liabilities on the Consolidated Balance Sheets.

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(1)	The FSIRS reclassification amounts are included in the Net interest deductions line item on the Consolidated Statements of Income.

(2)	These AOCI components are included in the computation of net periodic benefit cost (see Note 11 - Pension and Other Postretirement Benefits for additional details).

(3)	The regulatory adjustment represents the portion of the activity above that is expected to be recovered through rates in the future (the related regulatory asset is included in the Deferred charges and other assets line item on the Consolidated Balance Sheets).

(4)	Release of excess deferred taxes accumulated prior to December 22, 2017 (date of enactment of the TCJA), as a result of the adoption of ASU 2018-02 during the first quarter of 2018, which permitted such release.

(5)	Tax amounts related to the before-tax balance are calculated using a 24% effective rate after the release of previously stranded excess deferred taxes existing as a result of the TCJA; amounts prior to the December 22, 2017 enactment of the TCJA were calculated using a 38% effective rate.

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(6)	The FSIRS reclassification amounts are included in the Net interest deductions line item on the Consolidated Statements of Income.

(7)	These AOCI components are included in the computation of net periodic benefit cost (see Note 11 - Pension and Other Postretirement Benefits for additional details).

(8)	The regulatory adjustment represents the portion of the activity above that is expected to be recovered through rates in the future (the related regulatory asset is included in the Deferred charges and other assets line item on the Consolidated Balance Sheets).

(9)	Release of excess deferred taxes accumulated prior to December 22, 2017 (date of enactment of the TCJA), as a result of the adoption of ASU 2018-02 during the first quarter of 2018, which permitted such release.

(10)	Tax amounts related to the before-tax balances are calculated using a 24% effective rate after the release of previously stranded excess deferred taxes existing as a result of the TCJA; amounts prior to the December 22, 2017 enactment of the TCJA were calculated using a 38% effective rate.

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(1)	The Mutual funds category above is a balanced fund that invests in a diversified portfolio of common stocks, preferred stocks, and fixed-income securities. The fund seeks regular income, conservation of principal, and an opportunity for long-term growth of principal and income.

(2)

The private commingled equity funds include common collective trusts that invest in a diversified portfolio of domestic and international securities regularly traded on securities exchanges. These funds are shown in the above table at net asset value (“NAV”), which is the value of securities in the fund less the amount of any liabilities outstanding. Strategies employed by the funds include investment in:

•	International developed countries equities

•	Domestic equities

•	Emerging markets equities

(3)

The private commingled fixed income funds consist primarily of fixed income debt securities issued by the U.S. Treasury, government agencies, and fixed income debt securities issued by corporations. The fixed income fund investments may include the use of high yield, international fixed income securities and other instruments, including derivatives, to ensure prudent diversification over a broad spectrum

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(4)	With the exception of items (2) and (3), which are discussed in detail above, the Level 2 assets consist mainly of pooled funds and mutual funds. These funds are collective short-term funds that invest in Treasury bills and money market funds and are used as a temporary cash repository.

(5)	The insurance company general account contracts are annuity insurance contracts used to pay the pensions of employees who retired prior to 1989. The balance of the account disclosed in the above table is the contract value, which is the result of deposits, withdrawals, and interest credits.

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(1)	The number of securities granted includes 34,000 performance shares, which was derived by assuming that target performance will be achieved during the relevant performance period.

(2)	Includes shares for retiree payouts and those converted for taxes.

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•	Reduction of the federal income tax rate from 35% to 21%, effective January 1, 2018.

•	Bonus depreciation considerations for utility property placed-in-service after September 27, 2017.

•	100% bonus depreciation for most non-utility property placed-in-service after September 27, 2017.

•	Interest expense limitations for interest allocable to non-utility businesses. Interest expense allocable to utility businesses will have no limitation.

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(a)	Revenues are attributed to countries based on the location of customers.

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(1)	The sum of quarterly earnings (loss) per average common share may not equal the annual earnings (loss) per share due to the ongoing change in the weighted-average number of common shares.

(2)	Refer to Notes 1 and 18. Effective 2017, Southwest Gas Holdings, Inc. (“Company) is the successor equity issuer to Southwest Gas Corporation (“Southwest”). Both Southwest and Centuri became subsidiaries of the Company.

(3)	Periods prior to 2017 depict Centuri amounts as discontinued operations of Southwest.

(4)

Periods prior to 2018 depict revised operating income for the reclassification of non-service components of net periodic benefit costs, associated with pensions and other post-retirement benefits, out of the operations and maintenance line item of both the Company’s and Southwest’s Condensed Consolidated Statements of Income due to the adoption of ASU 2017-07. The resultant figures for Operating income, but not Net income, were increased accordingly to reflect reclassification. See Note 11 - Pension and Other Postretirement Benefits for further information relating to the adoption of this update.

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(a)	designed such disclosure controls and procedures, or caused such disclosure controls and procedures to be designed under our supervision, to ensure that material information relating to the registrant, including its consolidated subsidiaries, is made known to us by others within those entities, particularly during the period in which this report is being prepared;

(b)	designed such internal control over financial reporting, or caused such internal control over financial reporting to be designed under our supervision, to provide reasonable assurance regarding the reliability of financial reporting and the preparation of financial statements for external purposes in accordance with generally accepted accounting principles;

(c)	evaluated the effectiveness of the registrant’s disclosure controls and procedures and presented in this report our conclusions about the effectiveness of the disclosure controls and procedures, as of the end of the period covered by this report based on such evaluation; and

(d)	disclosed in this report any change in the registrant’s internal control over financial reporting that occurred during the registrant’s most recent fiscal quarter (the registrant’s fourth fiscal quarter in the case of an annual report) that has materially affected, or is reasonably likely to materially affect, the registrant’s internal control over financial reporting; and

(a)	all significant deficiencies and material weaknesses in the design or operation of internal control over financial reporting which are reasonably likely to adversely affect the registrant’s ability to record, process, summarize and report financial information; and

(b)	any fraud, whether or not material, that involves management or other employees who have a significant role in the registrant’s internal control over financial reporting.

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(a)	designed such disclosure controls and procedures, or caused such disclosure controls and procedures to be designed under our supervision, to ensure that material information relating to the registrant, including its consolidated subsidiaries, is made known to us by others within those entities, particularly during the period in which this report is being prepared;

(b)	designed such internal control over financial reporting, or caused such internal control over financial reporting to be designed under our supervision, to provide reasonable assurance regarding the reliability of financial reporting and the preparation of financial statements for external purposes in accordance with generally accepted accounting principles;

(c)	evaluated the effectiveness of the registrant’s disclosure controls and procedures and presented in this report our conclusions about the effectiveness of the disclosure controls and procedures, as of the end of the period covered by this report based on such evaluation; and

(d)	disclosed in this report any change in the registrant’s internal control over financial reporting that occurred during the registrant’s most recent fiscal quarter (the registrant’s fourth fiscal quarter in the case of an annual report) that has materially affected, or is reasonably likely to materially affect, the registrant’s internal control over financial reporting; and

(a)	all significant deficiencies and material weaknesses in the design or operation of internal control over financial reporting which are reasonably likely to adversely affect the registrant’s ability to record, process, summarize and report financial information; and

(b)	any fraud, whether or not material, that involves management or other employees who have a significant role in the registrant’s internal control over financial reporting.

(a)	designed such disclosure controls and procedures, or caused such disclosure controls and procedures to be designed under our supervision, to ensure that material information relating to the registrant, including its consolidated subsidiaries, is made known to us by others within those entities, particularly during the period in which this report is being prepared;

(b)	designed such internal control over financial reporting, or caused such internal control over financial reporting to be designed under our supervision, to provide reasonable assurance regarding the reliability of financial reporting and the preparation of financial statements for external purposes in accordance with generally accepted accounting principles;

(c)	evaluated the effectiveness of the registrant’s disclosure controls and procedures and presented in this report our conclusions about the effectiveness of the disclosure controls and procedures, as of the end of the period covered by this report based on such evaluation; and

(d)	disclosed in this report any change in the registrant’s internal control over financial reporting that occurred during the registrant’s most recent fiscal quarter (the registrant’s fourth fiscal quarter in the case of an annual report) that has materially affected, or is reasonably likely to materially affect, the registrant’s internal control over financial reporting; and

(a)	all significant deficiencies and material weaknesses in the design or operation of internal control over financial reporting which are reasonably likely to adversely affect the registrant’s ability to record, process, summarize and report financial information; and

(b)	any fraud, whether or not material, that involves management or other employees who have a significant role in the registrant’s internal control over financial reporting.

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(a)	designed such disclosure controls and procedures, or caused such disclosure controls and procedures to be designed under our supervision, to ensure that material information relating to the registrant, including its consolidated subsidiaries, is made known to us by others within those entities, particularly during the period in which this report is being prepared;

(b)	designed such internal control over financial reporting, or caused such internal control over financial reporting to be designed under our supervision, to provide reasonable assurance regarding the reliability of financial reporting and the preparation of financial statements for external purposes in accordance with generally accepted accounting principles;

(c)	evaluated the effectiveness of the registrant’s disclosure controls and procedures and presented in this report our conclusions about the effectiveness of the disclosure controls and procedures, as of the end of the period covered by this report based on such evaluation; and

(d)	disclosed in this report any change in the registrant’s internal control over financial reporting that occurred during the registrant’s most recent fiscal quarter (the registrant’s fourth fiscal quarter in the case of an annual report) that has materially affected, or is reasonably likely to materially affect, the registrant’s internal control over financial reporting; and

(a)	all significant deficiencies and material weaknesses in the design or operation of internal control over financial reporting which are reasonably likely to adversely affect the registrant’s ability to record, process, summarize and report financial information; and

(b)	any fraud, whether or not material, that involves management or other employees who have a significant role in the registrant’s internal control over financial reporting.

(1)	the Report fully complies with the requirements of section 13(a) or 15(d), as applicable, of the Securities Exchange Act of 1934; and

(2)	the information contained in the Report fairly presents, in all material respects, the financial condition and results of operations of the Company at the dates and for the periods indicated.

(1)	the Report fully complies with the requirements of section 13(a) or 15(d), as applicable, of the Securities Exchange Act of 1934; and

(2)	the information contained in the Report fairly presents, in all material respects, the financial condition and results of operations of the Company at the dates and for the periods indicated.

(1)	the Report fully complies with the requirements of section 13(a) or 15(d), as applicable, of the Securities Exchange Act of 1934; and

(2)	the information contained in the Report fairly presents, in all material respects, the financial condition and results of operations of Southwest Gas Corporation at the dates and for the periods indicated.

(1)	the Report fully complies with the requirements of section 13(a) or 15(d), as applicable, of the Securities Exchange Act of 1934; and

(2)	the information contained in the Report fairly presents, in all material respects, the financial condition and results of operations of Southwest Gas Corporation at the dates and for the periods indicated.