CHESAPEAKE ENERGY CORPORATION 2000 EMPLOYEE STOCK OPTION PLAN

Exhibit 10.1.6

CHESAPEAKE ENERGY CORPORATION

2000 EMPLOYEE STOCK OPTION PLAN

(as amended through June 6, 2008)

CHESAPEAKE ENERGY CORPORATION

2000 EMPLOYEE STOCK OPTION PLAN

Table of Contents

ARTICLE I

PURPOSE

Section 1.1 Purpose . This Stock Option Plan is established by Chesapeake Energy Corporation (the “Company”) to create incentives which are designed to motivate Eligible Employees to put forth maximum effort toward the success and growth of the Company and to enable the Company to attract and retain experienced individuals who by their position, ability and diligence are able to make important contributions to the Company’s success. Toward these objectives, the Plan provides for the granting of Options to Eligible Employees on the terms and subject to the conditions set forth in the Plan.

Section 1.2 Establishment . The Plan is effective as of April 26, 2000 and for a period of 10 years from such date. The Plan will terminate on April 25, 2010; however, it will continue in effect until all matters relating to the exercise of Options and administration of the Plan have been settled.

Section 1.3 Shares Subject to the Plan . Subject to Articles IV, VII and IX of this Plan, shares of stock covered by Options shall consist of Three Million (3,000,000) shares of Common Stock.

ARTICLE II

DEFINITIONS

Section 2.1 “Board” means the Board of Directors of the Company.

Section 2.2 “Code” means the Internal Revenue Code of 1986, as amended. Reference in the Plan to any Section of the Code shall be deemed to include any amendments or successor provisions to such Section and any regulations under such Section.

Section 2.3 “Committee” has the meaning set forth in Section 3.1.

Section 2.4 “Common Stock” means the common stock, par value $.01 per share, of the Company and, after substitution, such other stock as shall be substituted therefor as provided in Article VII or Article IX of the Plan.

Section 2.5 “Date of Grant” means the date on which the granting of an Option is authorized by the Committee or such later date as may be specified by the Committee in such authorization.

Section 2.6 “Disability” has the meaning set forth in Section 22(e)(3) of the Code.

Section 2.7 “Eligible Employee” means any employee of the Company, a Subsidiary or a partnership or limited liability company which the Company controls.

Section 2.8 “Exchange Act” means the Securities Exchange Act of 1934, as amended.

Section 2.9 “Executive Officer Participants” means Participants who are subject to the provisions of Section 16 of the Exchange Act with respect to the Common Stock.

Section 2.10 “Fair Market Value” means, as of any date, (i) if the principal market for the Common Stock is a national securities exchange or the Nasdaq stock market, the closing price of the Common Stock on that date on the principal exchange on which the Common Stock is then listed or admitted to trading; or (ii) if sale prices are not available or if the principal market for the Common Stock is not a national securities exchange and the Common Stock is not quoted on the Nasdaq stock market, the average of the highest bid and lowest asked prices for the Common Stock on such day as reported on the Nasdaq OTC Bulletin Board Service or by the National Quotation Bureau, Incorporated or a comparable service. If the day is not a business day, and as a result, clauses (i) and (ii) are inapplicable, the Fair Market Value of the Common Stock shall be determined as of the last preceding business day. If clauses (i) and (ii) are otherwise inapplicable, the Fair Market Value of the Common Stock shall be determined in good faith by the Committee.

Section 2.11 “Non-Executive Officer Participants” means Participants who are not subject to the provisions of Section 16 of the Exchange Act.

Section 2.12 “Nonqualified Stock Option” means an option to purchase shares of Common Stock which is not an incentive stock option within the meaning of Section 422(b) of the Code.

Section 2.13 “Option” means a Nonqualified Stock Option granted under Article VI of the Plan.

Section 2.14 “Option Agreement” means any written instrument that establishes the terms, conditions, restrictions, and/or limitations applicable to an Option in addition to those established by this Plan and by the Committee’s exercise of its administrative powers.

Section 2.15 “Participant” means an Eligible Employee to whom an Option has been granted by the Committee under the Plan.

Section 2.16 “Plan” means the Chesapeake Energy Corporation 2000 Employee Stock Option Plan.

Section 2.17 “Regular Stock Option Committee” means the Employee Compensation and Benefits Committee designated by the Board which shall consist of not less than one member of the Board.

Section 2.18 “Special Stock Option Committee” means a committee designated by the Board which shall consist of not less than two members of the Board who meet the definition of “non-employee directors” pursuant to Rule 16b-3, or any successor rule, promulgated under Section 16 of the Exchange Act.

Section 2.19 “Subsidiary” shall have the same meaning set forth in Section 424 of the Code.

ARTICLE III

ADMINISTRATION

Section 3.1 Administration of the Plan; the Committee . The Regular Stock Option Committee shall administer the Plan with respect to Non-Executive Officer Participants, including the grant of Options, and the Special Stock Option Committee shall administer the Plan with respect to Executive Officer Participants, including the grant of Options. Accordingly, as used in the Plan, the term “Committee” shall mean the Regular Stock Option Committee if it refers to Plan administration affecting Non-Executive Officer Participants or the Special Stock Option Committee if it refers to Plan administration affecting Executive Officer Participants. If in either case the Committee does not exist, or for any other reason determined by the Board, the Board may take any action under the Plan that would otherwise be the responsibility of the Committee.

Unless otherwise provided in the by-laws of the Company or resolutions adopted from time to time by the Board establishing the Committee, the Board may from time to time remove members from, or add members to, the Committee. Vacancies on the Committee, however caused, shall be filled by the Board. The Committee shall hold meetings at such times and places as it may determine. A majority of the Committee shall constitute a quorum, and the acts of a majority of the members present at any meeting at which a quorum is present shall be the valid acts of the Committee. Any action which may be taken at a meeting of the Committee may be taken without a meeting if all the members of the Committee consent to the action in writing.

Subject to the provisions of the Plan, the Committee shall have exclusive power to:

(a) Select the Eligible Employees to participate in the Plan.

(b) Determine the time or times when Options will be granted.

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(c) Determine the number of shares of Common Stock subject to any Option, all the terms, conditions (including performance requirements), restrictions and/or limitations, if any, of an Option, including the time and conditions of exercise or vesting, and the terms of any Option Agreement, which may include the waiver or amendment of prior terms and conditions or acceleration of the vesting or exercise of an Option under certain circumstances determined by the Committee.

(d) Determine whether Options will be granted singly or in combination.

(e) Take any and all other action it deems necessary or advisable for the proper operation or administration of the Plan.

Section 3.2 Committee to Make Rules and Interpret Plan . The Committee in its sole discretion shall have the authority, subject to the provisions of the Plan, to establish, adopt, or revise such rules and regulations and to make all such determinations relating to the Plan as it may deem necessary or advisable for the administration of the Plan. The Committee reserves the right to modify outstanding Options and awards unilaterally in any manner that is not adverse to the Option or award holder. The Committee’s interpretation of the Plan or any Options granted pursuant hereto and all decisions and determinations by the Committee with respect to the Plan shall be final, binding, and conclusive on all parties.

ARTICLE IV

GRANT OF OPTIONS

The Committee may, from time to time, grant Options to one or more Participants, provided, however, that:

(a) At least a majority of the shares of Common Stock underlying Options granted under the Plan, during the shorter of the three-year period commencing on the effective date of the Plan or the term of the Plan, must be granted to employees who are not Executive Officer Participants or directors of the Company.

(b) Any shares of Common Stock related to Options which terminate by expiration, forfeiture, cancellation or otherwise without the issuance of shares of Common Stock shall be available again for grant under the Plan.

(c) Common Stock delivered by the Company upon exercise of an Option under the Plan will be authorized and unissued shares or issued shares which have been reacquired by the Company (i.e., treasury shares).

(d) The Committee shall, in its sole discretion, determine the manner in which fractional shares arising under this Plan shall be treated.

(e) Upon the exercise of any Option,