BLACK HILLS CORPORATION NONQUALIFIED DEFERRED COMPENSATION PLAN

Exhibit 10.6

BLACK HILLS CORPORATION

NONQUALIFIED DEFERRED COMPENSATION PLAN

(As Amended and Restated effective January 1, 2009)

1.          Purpose of Plan and Effective Date . The original effective date of this Black Hills Corporation Nonqualified Deferred Compensation Plan (“Plan”) was the 1st day of June, 1999. The purpose of the Plan is to provide benefits to a select group of management or highly compensated employees who contribute materially to the continued growth, development and future business success of the Company. It is the intention of the Company that this Plan shall be administered as an unfunded benefit plan established and maintained for a select group of management or highly compensated employees. This Plan is hereby amended and restated effective January 1, 2009. It is the intention of the Company that this Plan shall comply with Code Section 409A and the regulations issued thereunder effective January 1, 2009. During the period from January 1, 2005 though December 31, 2008, it is the intention of the Company to operate this Plan in reasonable good faith compliance with Code Section 409A and the interim guidance issued thereunder.

2.          Definitions . For purposes of this Plan, the following phrases or terms have the indicated meanings unless otherwise clearly apparent from the context:

(a)       “Affiliate” shall mean any business organization or legal entity that directly or indirectly, controls, is controlled by or is under common control with the Company. For purposes of this definition, the term “control” (including the terms “controlling”, “controlled by”, and “under common control with”) includes the possession, direct or indirect, of the power to vote 50 percent or more of the voting equity securities, membership interest, or other voting interest, or to direct or cause the direction of the management and policies of such business organization or other legal entity, whether through the ownership of voting equity securities, membership interest, by contract, or otherwise.

(b)       “Base Salary” shall mean the compensation paid to a Participant by the Employer during a calendar year, including any compensation reduction under a cash or deferred arrangement under Section 401(k) of the Internal Revenue Code or under a flexible benefit program under Section 125 of the Internal Revenue Code but not including any amounts paid to the Participant as overtime, bonus, commission, or incentive compensation, nor reimbursements and expense allowances, fringe benefits, moving expenses, nonqualified deferred compensation, or welfare benefits.

(c)       “Base Salary Contribution” means that part of a Participant’s Base Salary that such Participant has elected to defer pursuant to Section 4.1.

(d)       “Beneficiary” shall mean the person, persons, or estate of a Participant, entitled to receive any benefits subsequent to the death of a Participant under a Beneficiary Designation form entered into in accordance with the terms of this Plan.

(e)       “Beneficiary Designation” shall mean the form of written agreement, by which the Participant names the Beneficiary(ies) under the Plan.

(g)       “Change in Control” shall mean a change in the ownership or effective control of the Company or a Subsidiary, or a change in the ownership of a substantial portion of the assets of the Company or a Subsidiary, as defined under Code Section 409A and the regulations issued thereunder.

(j)        “Company” shall mean Black Hills Corporation, a South Dakota corporation, with principal offices in the State of South Dakota.

(k)       “Employee” shall mean any person who is in the regular full-time employment of the Company or a Subsidiary, as determined by the personnel rules and practices of the Company or a Subsidiary. The term does not include persons who are retained by the Company or a Subsidiary solely as consultants.

(l)        “Employer” shall mean the Company and any Subsidiary that duly adopts the Plan.

(m)      “Incentive Contribution” means that portion of a Participant’s incentive award under the Company’s Short Term Annual Incentive Plan (“STIP”) which the Participant has elected to defer under the STIP and under Section 4.2.

(n)       Key Employee” shall mean a Participant who is a specified employee, as defined as in Code Section 409A and the regulations and other official guidance issued thereunder, and as determined in accordance with procedures established by the Committee.

(p)       “Participant’s Account” shall mean the memorandum account established and maintained by the Company for each Participant with respect to the Participant’s total interest in the Plan resulting from the Participant’s Base Salary Contributions and Incentive Contributions plus the earnings thereon.

(q)       “Performance Share Contributions” shall mean that portion of a Participant’s Performance Share Award under the Company’s Omnibus Incentive Compensation Plan (the "Omnibus Plan") which the Participant has elected to defer under the Participant’s Performance Share Award Agreement and the Omnibus Incentive Plan and under Section 4.4.

(r)        “Plan Year” shall mean the Plan’s accounting year of 12 months beginning on January 1 and ending on the following December 31.

(s)       "RSU Contribution" means a Participant's restricted stock unit award under the Company's Omnibus Incentive Compensation Plan or any successor plan that the Participant has deferred pursuant to the terms of the restricted stock unit agreement between the Participant and the Company (the "RSU Agreement") and under Section 4.3.

(t)        “Subsidiary” shall mean any business organization in which the Company, directly or indirectly owns a majority of its voting power or voting equity securities or equity interest and which the Board of Directors designates as a Subsidiary for purposes of this Plan.

(u)       “Termination of Employment” shall separation from service with the Company and all Affiliates for any reason other than death, in accordance with the provisions of Code Section 409A.

3.          Eligibility and Participation . In order to be eligible for participation in the Plan, an Employee must be selected by the Committee. The Committee, in its sole and absolute

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discretion, shall determine eligibility for participation from among management or highly compensated employees of the Employer in accordance with the purposes of the Plan.

4.1       Base Salary Contributions . Each Participant may elect to defer up to 50% of the Participant’s Base Salary for a Plan Year. An election to defer Base Salary must be made in writing prior to the beginning of a Plan Year. An election made with respect to a Participant’s Base Salary for a Plan Year becomes irrevocable on the last day of the prior Plan Year. Except as otherwise provided herein, the election may not be changed during the Plan Year and remains in place for subsequent Plan Years until changed or revoked. A change or revocation with respect to a subsequent Plan Year must be made in writing before the end of the prior Plan Year.

Notwithstanding the foregoing, a newly eligible Participant may, within 30 days after the date he becomes eligible, elect in writing to defer Base Salary for the Plan Year in which he first becomes eligible, but only with respect to Base Salary earned subsequent to the election. Except as otherwise provided herein, such election is irrevocable with respect to the remainder of the Plan Year and remains in place for subsequent Plan Years until changed or revoked. A change or revocation with respect to a subsequent Plan Year must be made in writing before the end of the prior Plan Year.

The Participant’s Base Salary Contribution shall be allocated to that Participant’s Account on a monthly basis.

The Base Salary Contribution election of a Participant who receives an emergency withdrawal due to an Unforeseeable Emergency under Section 7.1 or a hardship distribution under a tax-qualified 401(k) plan maintained by the Company shall be cancelled. A Participant whose Base Salary Contribution election is cancelled due to an Unforeseeable Emergency under Section 7.1 may elect to resume Base Salary Contributions with respect to a Plan Year beginning after such distribution is made by making an election prior to the beginning of such Plan Year. A Participant whose Base Salary Contribution election is cancelled due to a hardship withdrawal under a tax-qualified 401(k) plan maintained by the Company may elect to resume Base Salary Contributions with respect to a Plan Year beginning at least 6 months after such withdrawal is made by making an election prior to the beginning of such Plan Year.

4.2       Incentive Contributions . A Participant may elect to defer the receipt of all or any portion of a Participant’s incentive award under the STIP, including shares of Company stock. The deferral election must be filed by June 30 of the Plan Year prior to the Plan Year in which the Award will be determined or, if earlier, by the day before the date on which the Incentive Award has become readily ascertainable (as defined for purposes of Section 409A of the Internal Revenue Code). In no event shall an election to defer be effective unless the Participant is an employee at all times from the first day of the Plan Year prior to the Plan Year in which the Award will be determined (or, if later, the date the performance measures under the STIP for the Plan Year have been established) until the date the election is made. The amount of the incentive award deferred shall be allocated to a Participant’s Account as of the date it would have been distributed if no deferral election had been made. In the event that Participant defers a stock award under the STIP, then the Company shall establish within the Participant’s Account a common stock equivalent memorandum account (“Stock Account”) and shall credit the Stock Account with Company common stock equivalents, including fractional equivalents. Appropriate adjustments shall be made to the Stock Account for stock splits, stock dividends, mergers, consolidation and other similar circumstances affecting the Company common stock.

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4.3        RSU Contributions . A Participant who has been granted an award of Restricted Shares under the Omnibus Plan may elect to receive the entire award in the form of restricted stock units and defer the receipt thereof as an RSU Contribution. The election to receive restricted stock units must be made before the beginning of the Plan Year in which the grant of Restricted Shares is made. The amount of the award deferred under the Omnibus Plan and RSU Agreement shall be allocated to a Participant's Account upon receipt by the Company of the Participant's executed RSU Agreement. If the Participant does not vest in the award under the terms of the RSU Agreement, the deferral of the RSU Contribution shall be null and void. The Company shall establish within the Participant's Account a Stock Account for the RSU contribution (as defined in Section 4.2) and shall credit the Stock Account with Company common stock equivalents (but not actual shares), including fractional equivalents. Appropriate adjustments shall be made to the Stock Account for Stock splits, stock dividends, mergers, consolidation and other similar circumstances affecting the Company common stock. A Participant's RSU Contributions shall remain subject to, and shall vest in accordance with, the terms of the applicable RSU Agreement.

4.4       Performance Share Contributions . A Participant may elect under the terms of the Company’s Omnibus Plan and his Performance Share Award Agreement, to defer the receipt of all or any portion of a Participant’s Performance Share Award thereunder, including shares of Company stock. The election to defer must be made in writing before the beginning of the Performance Period specified in the Performance Share Award Agreement. The amount of the award deferred under the Omnibus Plan and Performance Share Award Agreement shall be allocated to a Participant's Account upon receipt by the Company of the Participant's deferral election. If the Participant does not vest in the award under the terms of the Performance Share Award Agreement, the deferral of the Performance Share Contribution shall be null and void. In the event that Participant defers a stock award, then the Company shall establish within the Participant’s Account a common stock equivalent memorandum account (“Stock Account”) and shall credit the Stock Account with Company common stock equivalents, including fractional equivalents. Appropriate adjustments shall be made to the Stock Account for stock splits, stock dividends, mergers, consolidation and other similar circumstances affecting the Company common stock. A Participant's Performance Share Contributions shall remain subject to, and shall vest in accordance with, the terms of the applicable Performance Share Award Agreement.

5.          Earnings on Participant’s Acc