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**EXCLUSIVITY      AGREEMENT**

**Agreement**
**Effective      Date**
**USEG**
**CBAG**
**Sellers**
**SXR      Uranium One Inc., **
**Buyer**

**Recitals**

| A. | The                Sellers are in the natural resource business and carry on, directly                and                through subsidiary and affiliated entities, a uranium exploration                and                development business with the goal of creating a United States uranium                mining and milling business (the “**Business**”). |
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| B. | In                accordance with a term sheet dated June 22, 2006 signed by the Parties                (the “**Term                Sheet**”),                the Sellers wish to sell, and the Buyer directly or through one or                more                wholly-owned subsidiaries thereof wishes to purchase, the uranium                assets                of the Sellers used in the Business listed in Schedule A to the Term                Sheet, as amended on the date hereof (the “**Assets**”)                for the consideration and on the terms and conditions described therein. |
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| C. | The                purchase and sale of the Assets is subject, among other things, to                the                successful completion by the Buyer of a detailed due diligence                investigation of the Assets, to the preparation and execution of                a                mutually satisfactory definitive acquisition agreement (the “**Definitive                Agreement**”)                containing terms and conditions consistent with the Term Sheet and                the                provisions hereof, to the receipt of all required regulatory and                shareholder approvals and to the approval of the boards of directors                of                each party hereto. |
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| D. | In                connection therewith, the Sellers have agreed to grant the Buyer                exclusive                rights as more particularly set forth herein to negotiate the Definitive                Agreement and to conduct its due diligence investigation of the Assets. |
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| E. | Concurrently                herewith, the parties have entered into a confidentiality and                non-disclosure agreement (the “**Confidentiality                Agreement**”)                to replace and supersede the confidentiality agreement dated November                18,                2005 between USEG and Aflease Gold and Uranium Resources Limited. |
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**Agreement**

**Parties**
**Party**

| (a)   | In                consideration of the receipt of the Fee (as hereinafter defined),                the                Sellers hereby grant to the Buyer for the Term (as hereinafter defined)                the exclusive right, at the Buyer’s sole cost and expense, to review all                information and data in the control or possession of the Sellers                relating                to the Assets and to perform all investigations, inquiries and studies                with respect to the Assets as the Buyer may reasonably require for |
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| (b)   | During                the Term, the Sellers (i) will not, and will not permit any other                person                or company to, directly or indirectly through any director, officer,                agent, affiliate, employee or otherwise: (A) solicit, initiate or                encourage the submission of any proposal or offer, or have discussions,                engage in negotiations or enter into any understanding, agreement                or                commitment with, or accept any proposal from, any person other than                the                Buyer relating to the acquisition or purchase of the Assets or the                Business; or (B) furnish or agree to furnish to any other person                any                information regarding the Assets or the Business except as required                by law                for reporting, permitting or conducting business in the ordinary                course or                as required by any existing agreement; (ii) will inform any person                making                inquiry with respect thereto of the existence of this Agreement;                and (iii)                will inform the Buyer of any such inquiry. |
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| (c)   | Notwithstanding                Section 1(b), the Sellers may continue to pursue the acquisition                of                additional uranium assets that Sellers have been in pursuit of as                of the                date hereof or wish to pursue and in either such case the Buyer will                have                the right to review and approve, or decline to approve, the acquisition                by                the Sellers of any such assets during the Term. If the Buyer approves                such                acquisition and the purchase and sale of the Assets is completed,                the                Buyer will on the closing thereof pay to the Sellers the reasonable                costs                they have incurred in pursuing such acquisition plus 5%, such payment                to                be made in addition to the purchase price payable for the Assets                on such                closing. If the Buyer declines to approve such acquisition, the Sellers                may make the acquisition for their own account or otherwise deal                in such                assets without the Buyer’s further consent or participation, and the Buyer                will have no obligation or liability to reimburse the Sellers for                any of                the costs incurred by them in connection with such pursuit or acquisition. |
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**Fee**

| (a) | if,                prior to the end of the Term, the Parties enter into a Definitive                Agreement, the Fee will be credited to, and subtracted from, the                purchase                price due from the Buyer to the Sellers pursuant to the terms thereof; |
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| (b) | if,                on or before the end of the Term, (i) the Parties do not enter into                a                Definitive Agreement, (ii) the Buyer determines in its sole discretion                that it does not desire to acquire the Assets, or (iii) subject to                Section                2(c), this Agreement is terminated pursuant to Section 7, the Fee                automatically will be deemed earned by the Sellers and will not be                reimbursable to the Buyer; and |
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| (c) | if                this Agreement is terminated by the Buyer pursuant to Section 7(a)                by                reason of the material breach hereof by the Sellers or either of                them, or                by reason of the Sellers’ inability to obtain a required third party                consent or approval before the end of the Term, the Fee will be                reimbursable by the Sellers to the Buyer forthwith on receipt by                the                Sellers of the Buyer’s notice of termination. |
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**Term**

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| (a) | The                Buyer may terminate this Agreement at any time during the Term by                giving                written notice to the Sellers of such termination, whether or not                the                Sellers or either of them are in material breach hereof, and, subject                to                Section 7(c), such termination will become effective upon the Sellers’                receipt of such notice, without further action by either                Party. |
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| (b) | The                Sellers may terminate this Agreement at any time during the Term                by giving                written notice to the Buyer of such termination if the Buyer is in                material breach hereof and, subject to Section 7(c), such termination                will                become effective upon the Buyer’s receipt of such notice, without further                action by either Party. |
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| (c) | Notwithstanding                any other provision of this Agreement, if the Buyer or the Sellers                give                written notice of termination under Section 7(a) or 7(b) by reason                of a                material breach hereof, such termination will not become effective                unless                the Party giving such notice (the “notifying party”): |
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|   | (i) | sets                out in such notice of termination the basis for its belief that a                material                breach has occurred; |
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|   | (iii) | declines,                in a written notice given to the receiving party within 10 business                days                of receiving such notice of reply, to accept such notice of reply; |
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| (d) | Notwithstanding                any other provision of this Agreement, the Confidentiality Agreement                and                the provisions of Sections 2, 9, 11 and 13 of this Agreement, will                survive                any termination of this Agreement. |
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| (a) | If                any Party brings any proceedings to enforce any of the terms hereof,                the                prevailing Party will be entitled to recover from the other Party                or                Parties reimbursement for all reasonable expenses, costs and attorneys'                and experts’ fees incurred in connection                therewith. |
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| (b) | No                Party will be liable to any other Party for indirect or consequential                damages with respect to this Agreement or in connection with the                breach                hereof. |
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| (c) | The                Term Sheet, this Agreement and the Confidentiality Agreement contain                the                entire agreement of the Parties hereto with respect to the subject                matter                hereof and supersede all prior understandings and agreements, whether                written or oral, with respect thereto. |
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| (d) | No                Party may assign this Agreement without the prior written consent                of the                other Parties except that the Buyer may assign this Agreement to                one or                more direct or indirect wholly-owned subsidiaries thereof without                the                prior written consent of the Sellers. |
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| (e) | Nothing                in this Agreement will be deemed to create rights in or benefits                for any                third parties. |
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| (f) | This                Agreement will not be amended or modified in any way except by an                instrument signed by each Party. |
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**[REMAINDER      OF PAGE INTENTIONALLY BLANK]**

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**U.S.      Energy Corp.**

**Crested      Corp.**

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**Sxr      Uranium One Inc. **

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