CIMAREX ENERGY CO. CHANGE IN CONTROL SEVERANCE PLAN

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EXHIBIT 10.20

CIMAREX ENERGY CO.

CHANGE IN CONTROL SEVERANCE PLAN

(Effective April 1, 2005; Amended and Restated Effective January 1, 2009)

INTRODUCTION

        The Board of Directors of Cimarex Energy Co. recognizes that, as is the case with many publicly held corporations, there exists the possibility of a Change in Control of the Company. This possibility and the uncertainty it creates may result in the loss or distraction of employees of the Company and its Subsidiaries to the detriment of the Company and its stockholders.

        The Board considers the avoidance of such loss and distraction to be essential to protecting and enhancing the best interests of the Company and its stockholders. The Board also believes that when a Change in Control is perceived as imminent, or is occurring, the Board should be able to receive and rely on disinterested service from employees regarding the best interests of the Company and its stockholders without concern that employees might be distracted or concerned by the personal uncertainties and risks created by the perception of an imminent or occurring Change in Control.

        In addition, the Board believes that it is consistent with the employment practices and policies of the Company and its Subsidiaries and in the best interests of the Company and its stockholders to treat fairly its employees whose employment terminates in connection with or following a Change in Control.

        Accordingly, the Board has determined that appropriate steps should be taken to assure the Company and its Subsidiaries of the continued employment and attention and dedication to duty of their employees and to seek to ensure the availability of their continued service, notwithstanding the possibility, threat or occurrence of a Change in Control.

        The Plan provides for nonqualified deferred compensation within the meaning of section 409A of the Internal Revenue Code of 1986, as amended, which became effective January 1, 2005. The Internal Revenue Service has published final regulations and other guidance interpreting section 409A. The Board wishes to amend the Plan document to incorporate the provisions necessary to comply with the requirements of section 409A.

        In order to fulfill the above purposes, the Board adopted the Cimarex Energy Co. Change in Control Severance Plan (the "Plan") effective as of the Effective Date, as set forth below. The Board hereby amends and restates the Plan, effective as of January 1, 2009, to bring the Plan into compliance with section 409A.

ARTICLE I
ESTABLISHMENT OF PLAN

        As of April 1, 2004, the Company established a separation compensation plan known as the Cimarex Energy Co. Change in Control Severance Plan, as set forth in this document. The Company hereby amends and restates the Plan in its entirety, effective as of January 1 2009.

ARTICLE II
DEFINITIONS

        As used herein the following words and phrases shall have the following respective meanings unless the context clearly indicates otherwise.

        (a)     Affiliate.     Any entity which controls, is controlled by or is under common control with the Company.

        (b)     Annual Average Compensation.     The amount determined by adding (i) the amount received by the Participant as regular annual base salary (hereinafter referred to as "Base Salary") during the 24-consecutive month period ending on or immediately prior to the Date of Termination, including

compensation converted to other benefits under a flexible pay arrangement maintained by the Company or any Affiliate or deferred pursuant to a written plan or agreement with the Company or any Affiliate but excluding overtime pay, allowances, premium pay or any similar payment and (ii) the amount of cash incentive awards received by the Participant pursuant to the Company's annual incentive bonus arrangement (hereinafter the "Annual Incentive Bonus") during the 24-consecutive month period ending on or immediately prior to the Date of Termination, and then dividing that sum by two. If a Participant was not employed by the Company for the full 24 months prior to the Date of Termination or otherwise did not receive Base Salary and Annual Incentive Bonus with respect to the full 24 months immediately prior to the Date of Termination, the amounts of Base Salary and Annual Incentive Bonus compensation actually received by the Participant shall be annualized over the two consecutive 12-month periods ending on or immediately prior to the Date of Termination.

        (c)     Average Incentive Bonus.     The amount of Annual Incentive Bonus compensation that the Participant would have received with respect to the Company's fiscal year during which the Date of Termination occurs if the Participant were to receive the average amount paid to all employees covered by the Company's Annual Incentive Bonus plan for such fiscal year.

        (d)     Board.     The Board of Directors of Cimarex Energy Co.

        (e)     Cause.     With respect to any Participant: (i) the willful and continued failure of the Participant to perform substantially the Participant's duties with the Company or one of its Affiliates (other than any such failure resulting from incapacity due to physical or mental illness), after a written demand for substantial performance is delivered to the Participant by the Board or a senior officer of the Company which specifically identifies the manner in which the Board or senior officer believes that the Participant has not substantially performed the Participant's duties, (ii) the willful engaging by the Participant in misconduct which is materially and demonstrably injurious to the Company or any Affiliate, or (iii) a business crime or felony involving moral turpitude of which the Participant is convicted or pleads guilty. For purposes of this definition, no act or failure to act on the part of the Participant shall be considered "willful" unless it is done, or omitted to be done, by the Participant in bad faith or without reasonable belief that the Participant's action or omission was in the best interests of the Company or any Affiliate. Any act or failure to act based upon authority given pursuant to a resolution duly adopted by the Board or upon the instructions of the Chief Executive Officer or a senior officer of the Company or any Affiliate or based upon the advice of counsel for the Company shall be conclusively presumed to be done, or omitted to be done, by the Participant in good faith and in the best interests of the Company.

        (f)     Change in Control.     The occurrence of any of the following events on or after the Effective Date of this Plan, provided that in the event Code section 409A applies to payments under this Plan, a Change of Control shall be deemed to have occurred only if the event is also a change of control within the meaning of Code section 409A and the regulations and other guidance promulgated thereunder or not inconsistent therewith.

        (i)    The acquisition by any individual, entity or group (within the meaning of Section 13(d)(3) or 14(d)(2) of the Securities Exchange Act of 1934, as amended (the "Exchange Act")) (a "Person") of beneficial ownership (within the meaning of Rule 13d-3 promulgated under the Exchange Act) of 30% or more of either (x) the then outstanding shares of common stock (the "Common Stock") of the Company (the "Outstanding Company Common stock") or (y) the combined voting power of the then outstanding voting securities of the Company entitled to vote generally in the election of directors (the "Outstanding Company Voting Securities"); provided, however, that for purposes of this subsection (i), the following acquisitions shall not constitute a Change in Control: (A) any acquisition directly from the Company, (B) any acquisition by the Company, (C) any acquisition by any employee benefit plan (or related trust) sponsored or maintained by the Company or any corporation controlled by the Company, (D) any acquisition by

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any corporation pursuant to a transaction that complies with clauses (A) and (B) of paragraph (iii) below; or

        (ii)   During any period of twelve months beginning after the Effective Date, individuals who, as of the Effective Date, constitute the Board (the "Incumbent Board") cease for any reason to constitute at least a majority of the Board; provided, however, that any individual becoming a director at the beginning of such twelve-month period, whose election, appointment or nomination for election by the Company's stockholders, was approved by a vote of at least a majority of the directors then comprising the Incumbent Board shall be considered as though such individual were a member of the Incumbent Board, but excluding, for this purpose, any such individual whose initial assumption of office occurs as a result of an actual or threatened election contest with respect to the election or removal of directors or other actual or threatened solicitation of proxies or consents by or on behalf of a Person other than the Board; or

        (iii)  The closing of a reorganization, share exchange or merger (a "Business Combination"), in each case, unless, following such Business Combination, (A) all or substantially all of the individuals and entities who were the beneficial owners, respectively, of the Outstanding Company Common Stock and Outstanding Voting Securities immediately prior to such Business Combination will beneficially own, directly or indirectly, more than 40% of, respectively, the then outstanding shares of common stock and the combined voting power of the then outstanding voting securities entitled to vote generally in the election of directors, as the case may be, of the corporation resulting from such Business Combination (including, without limitation, a corporation which as a result of such transaction will own the Company through one or more subsidiaries) in substantially the same proportions as their ownership, immediately prior to such Business Combination of the Outstanding Company Common Stock and Outstanding Company Voting Securities, as the case may be and (B) at least a majority of the members of the board of directors of the corporation resulting from such Business Combination were members of the Incumbent Board at the time of the execution of the initial agreement, or of the action of the Board, providing for such Business Combination or were elected, appointed or nominated by the Board; or

        (iv)  The closing of (1) a complete liquidation or dissolution of the Company or, (2) the sale or other disposition of all or substantially all of the assets of the Company, other than to a corporation, with respect to which following such sale or other disposition, (A) more than 40% of, respectively, the then outstanding shares of common stock of such corporation and the combined voting power of the then outstanding voting securities of such corporation entitled to vote generally in the election of directors is then beneficially owned, directly or indirectly, by all or substantially all of the individuals and entities who were the beneficial owners, respectively, of the Outstanding Company Common Stock and Outstanding Company Voting Securities immediately prior to such sale or other disposition in substantially the same proportion as their ownership, immediately prior to such sale or other disposition, of the Outstanding Company Common Stock and Outstanding Company Voting Securities, as the case may be, and (B) at least a majority of the members of the board of directors of such corporation were members of the Incumbent Board at the time of the execution of the initial agreement, or of the action of the Board, providing for such sale or other disposition of assets of the Company or were elected, appointed or nominated by the Board.

        (g)     Code.     The Internal Revenue Code of 1986, as amended from time to time.

        (h)     Committee.     The Governance Committee of the Board.

        (i)     Company.     Cimarex Energy Co. and any successor to such entity.

        (j)     Date of Termination.     The date on which a Participant ceases to be an Employee of the Company and its Affiliates as a result of a "separation from service" as determined in accordance with

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the provisions of Section 409A of the Code and the Internal Revenue Service and Treasury guidance thereunder.

        (k)     Disability.     A Participant shall be disabled for purposes of this Plan if the Participant (1) 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 (2) is, 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, receiving income replacement benefits for a period of not less than three months under an accident and health plan covering employees of the Company. The foregoing definition of "Disability" shall be interpreted in a manner consistent with Section 409A of the Code and the Internal Revenue Service and Treasury guidance thereunder.

        (l)     Effective Date.     The effective date of this amendment and restatement is January 1, 2009.

        (m)     Employee.     Any employee of an Employer.

        (n)     Employer.     The Company or any Subsidiary which participates in the Plan pursuant to Article V hereof or, under the circumstances set forth in the second sentence of Section 3.1 hereof, any Subsidiary or Affiliate described in such sentence.

        (o)     ERISA.     The Employee Retirement Income Security Act of 1974, as amended from time to time.

        (p)     Good Reason.     With respect to any Participant, without such Participant's written consent, (i) any reduction in the Participant's annual Base Salary, as in effect during the 120-day period immediately preceding the Change in Control (or as such amount may be increased from time to time) other than as a result of an isolated and inadvertent action not taken in bad faith and which is remedied by the Company or the Employer promptly after receipt of notice thereof given by the Participant, (ii) a material reduction in the Participant's annual incentive compensation opportunity, as in effect as of the date of the Change in Control, provided that the Company may modify the Company's annual incentive compensation arrangement subsequent to the date of a Change in Control so long as such change is applied to all Employees of the Company in a comparable manner, (iii) the Company or the Employer requiring the Participant to relocate his or her principal place of business to another metropolitan area which is more than 50 miles from his or her previous office location, (iv) following the date of a Change in Control, the failure of the Company to provide generally comparable benefits, provided that the Company may increase employee contributions under benefit plans from time to time and/or it may modify benefits as required by law or competitive market conditions, so long as any such modifications apply in a comparable manner to all employees enrolled in such benefit plan or plans at a comparable level of benefits.

        (q)     Participant.     An individual who is designated as such pursuant to Section 3.1.

        (r)     Plan.     The Cimarex Energy Co. Change in Control Severance Plan.

        (s)     Separation Benefits.     The benefits described in Section 4.2 that are provided to qualifying Participants under the Plan.

        (t)     Subsidiary.     Any corporation in which the Company, directly or indirectly, holds a majority of the voting power of such corporation's outstanding shares of capital stock.

        (u)     Year of Service.     A Year of Service shall be credited to a Participant for each full twelve months of employment with the Company or any Affiliate, Subsidiary or predecessor to the Company, including but not limited to Key Production Company and Helmerich & Payne, Inc. A month of service shall be credited for each full month of employment with such entities. Service shall also be credited

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for purposes of the Plan to the extent required by any agreement between the Company and an entity acquired by or merged with or into the Company or any Affiliate or Subsidiary of the Company.

ARTICLE III
ELIGIBILITY

        3.1     Participation.     Each Employee who is actively employed by the Company on the date of a Change in Control shall be a Participant in the Plan. For this purpose, an Employee who is on a leave of absence approved by the Company in writing or authorized by applicable state or federal law on the date of a Change in Control shall be a Participant in the Plan. Any person (a) who provides services to the Company or an Affiliate under an agreement, contract, or any other arrangement pursuant to which the individual is initially classified as an independent contractor or (b) whose remuneration for services has not been treated initially as subject to the withholding of federal income tax pursuant to Code section 3401 shall not be treated as an Employee and shall not be eligible to be a Participant in this Plan, even if the individual is subsequently reclassified as a common-law employee as a result of a final decree of a court of competent jurisdiction or the settlement of an administrative or judicial proceeding. If a Participant's employment is transferred from an Employer to a Subsidiary or Affiliate of the Company which is not a participating Employer under the Plan, the provisions of the Plan will continue to apply to such Participant while employed by such Subsidiary or Affiliate.

        3.2     Duration of Participation.     A Participant shall only cease to be a Participant in the Plan as a result of an amendment or termination of the Plan complying with Article VII of the Plan, or when he ceases to be an Employee of any Employer, unless, at the time he ceases to be an Employee, such Participant is entitled to payment of a Separation Benefit as provided in the Plan or there has been an event or occurrence constituting Good Reason that would enable the Participant to terminate his employment and receive a Separation Benefit. A Participant entitled to payment of a Separation Benefit or any other amounts under the Plan shall remain a Participant in the Plan until the full amount of the Separation Benefit and any other amounts payable under the Plan have been paid to the Participant.

ARTICLE IV
SEPARATION BENEFITS

        4.1     Terminations of Employment Which Give Rise to Separation Benefits Under This Plan.     A Participant shall be entitled to Separation Benefits as set forth in Section 4.2 below if, at any time following a Change in Control and prior to the second anniversary of the Change in Control, the Participant's employment is terminated as a result of a "separation from service" (as determined in accordance with Section 409A of the Code and the Internal Revenue Service and Treasury guidance thereunder) (a) by the Participant's Employer for any reason other than Cause, death, or Disability or (b) by the Participant for Good Reason within 120 days after the Participant has knowledge of the occurrence of a Good Reason.

        4.2     Separation Benefits.     

        (a)   If a Participant's employment is terminated in circumstances entitling such participant to Separation Benefits pursuant to Section 4.1, the Company shall provide to such Participant cash payments as set forth in subsection (b) below, and shall provide to the Participant the continued benefits as set forth in subsection (c) below. For purposes of determining the benefits set forth in subsections (b) and (c), if the termination of the Participant's employment is for Good Reason based upon a reduction of the Participant's annual Base Salary, as described in Article II(p), a material reduction in the Participant's annual incentive compensation opportunity as provided in Article II(p), or the failure to provide comparable employee benefits as provided in Article II(p), such reduction shall be ignored.

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        (b)   The cash payments referred to in Section 4.2(a) shall be the following amounts:

        (i)    the product of (A) the Participant's Average Incentive Bonus and (B) a fraction, the