VOTING AGREEMENT

This Voting Agreement (“ Agreement ”) is entered into as of January 23, 2007 by and between U.S. Energy Corp., a Wyoming corporation (“ USE ”); the individual shareholders (the “ Individual Shareholders ”) of Crested Corp., a Colorado corporation (“ Crested ”) identified on the signature page; and Crested. Each of USE and the Individual Shareholders are referred to as a “ Shareholder ;” collectively, those parties are referred to as the “ Shareholders .”

Whereas, USE and Crested have entered into an Agreement and Plan of Merger (the “ Merger Agreement ”) providing for the merger (the “ Merger ”), dated as of the date hereof. Terms not defined in this Agreement have the meanings defined in the Merger Agreement.

Whereas, the Merger Agreement requires that the Shareholders, solely in their capacities as holders of Crested common stock, enter into, and the Shareholders have agreed to enter into, this Voting Agreement.

NOW, THEREFORE, in consideration of the premises and other good and valuable consideration, the receipt and sufficiency of which is hereby acknowledged, the parties hereby agree as follows:

1.   Representations and Warranties of the Shareholders . Each of the Shareholders represents and warrants to Crested as follows:

(a)   Authority; Binding Obligation . The Shareholder has all necessary power and authority to enter into this Agreement and perform all of the Shareholder’s obligations hereunder. This Agreement has been duly and validly executed and delivered by the Shareholder and constitutes a valid and legally binding obligation of the Shareholder, enforceable against the Shareholder in accordance with its terms.

(b)   Ownership of Shares . The Shareholder is the beneficial owner or record holder of the number of shares of Crested listed under the Shareholder’s name on the signature page (the “ Existing Shares ” and, together with any shares of Crested common stock the record or beneficial ownership of which is acquired by the Shareholder after the date hereof, the “ Shares ” including (only for the individual Shareholders) any shares of common stock of Crested which are acquired by the Company Stock Option Payment under the Merger Agreement (such latter shares hereafter referred to as the “ Option Shares ”) and, as of the date hereof, the Existing Shares and Option Shares constitute all the shares of Crested common stock owned of record or beneficially by the Shareholder). Provided , that the Existing Shares shown for each individual Shareholder does not reflect that person’s beneficial ownership (as defined in SEC rule 13d-3) of shares of Crested common stock which he holds as an officer or director of USE.

With respect to the Existing Shares, the Shareholder has, without any restrictions except as imposed by law and this Agreement, (i) sole voting power and sole power to issue instructions with respect to or otherwise engage in the actions set forth in Section 2; (ii) sole power of disposition; and (iii) sole power to demand appraisal rights under Article 113 of the Colorado Business Corporation Act. With respect to the Option Shares, the Shareholder will have sole power of disposition.

(c)   No Conflicts . Neither the execution, delivery and performance of this Agreement nor the consummation of the transactions contemplated hereby will conflict with or constitute a violation of or a default under (with or without notice, lapse of time, or both) any contract, agreement, voting agreement, shareholders’ agreement, trust agreement, voting trust, proxy, power of attorney, pooling arrangement, note, mortgage, indenture, instrument, arrangement or other obligation or restriction of any kind to which the Shareholder is a party or to which the Shareholder or the Shareholder’s Shares are subject to or bound.

2.   Voting Agreement and Agreement Not to Transfer .

(a)    The Shareholder agrees to vote or cause to be voted all of the Shareholder’s Existing Shares

(i)   consistent with the vote of holders of a majority of the shares of Crested common stock not held by the Shareholders (the “ Majority Vote of the Minority Holders ”), whether in favor of, or against, the approval of the Merger Agreement at a meeting of the Crested shareholders, as well as any other matters required to be approved by the Crested shareholders at the meeting wherein the Merger is voted upon by the Crested shareholders. Provided , that USE may elect not to vote in favor of the Merger, even if the Merger Agreement has been approved by Majority Vote of the Minority Holders, as such election is permitted pursuant to the termination provisions of the Merger Agreement.

(ii)   against any action or agreement that would result in a breach in any material respect of any covenant, representation or warranty or any other obligation or agreement of Crested under the Merger Agreement; and

(iii)   against the following actions (other than the Merger or the consummation of any actions contemplated by the Merger Agreement):

(A)   any extraordinary corporate transactions, such as a merger, consolidation or other business combination involving Crested;

(B)   any sale, lease, transfer or disposition of a material amount of the assets of Crested, except as may be contemplated by the Company SEC Reports.;

(C)   any change in the majority of the board of directors of Crested;

(D) any material change in the present capitalization of Crested;

(E)   any amendment of Crested’s articles of incorporation or bylaws;

(F)   any other change in the corporate structure, business, assets or ownership of Crested (but a vote in favor of amending the Crested Incentive Stock Option Plan to allow for cashless exercise shall be permitted); or

(G)   any other action which is intended, or could reasonably be expected to, impede, interfere with, delay, postpone, discourage or adversely affect the contemplated economic benefits to Crested of the Merger and the transactions contemplated by the Merger Agreement.

(b)   The Shareholder agrees not to (i) sell, transfer, convey, assign or otherwise dispose of any of his, her or its Existing Shares, or any of the Option Shares if an Individual Shareholder exercises his or her Option before the Effective Date; or (ii) pledge, mortgage or otherwise encumber such Existing or Option Shares.

3.   Cooperation . The Shareholder agrees that he, she or it will not (directly or indirectly) initiate, solicit, encourage or facilitate any Takeover Proposal.

4.   Shareholder Capacity . The Individual Shareholder is entering into thi