Exhibit 10.3

FOURTH AMENDMENT TO

ESCROW AGREEMENT

This FOURTH AMENDMENT TO ESCROW AGREEMENT (this “Amendment”) is made as of December 10, 2013 by and among the Karlsson Group, Inc., an Arizona corporation (“Lender”), Prospect Global Resources, Inc., a Nevada corporation (“Obligor”), and JPMorgan Chase Bank, N.A., a national banking association, as escrow agent (together with any successor in such capacity, the “Escrow Agent”), with respect to the following facts:

RECITALS

WHEREAS, Lender, Obligor and Escrow Agent entered into that certain Escrow Agreement dated as of April 15, 2013 (the “Original Agreement”);

WHEREAS, Lender, Obligor and Escrow Agent entered into that certain Amendment to Escrow Agreement dated as of June 26, 2013, that certain Second Amendment to Escrow Agreement dated as of August 14, 2013, and that certain Third Amendment to Escrow Agreement dated as of September 13, 2013, amending the Original Agreement (as amended thereby, and as hereby and hereafter amended from time to time, the “Escrow Agreement”);

WHEREAS, Lender, Obligor, and the other parties thereto entered into that certain Fourth Extension Agreement dated as of the date hereof (the “Fourth Extension”); and

WHEREAS, it is a condition to the effectiveness of the Fourth Extension that the parties hereto amend the Escrow Agreement.

NOW, THEREFORE, for valuable consideration, the receipt and sufficiency of which are hereby acknowledged, the parties hereto do hereby agree as follows:

AGREEMENT

1.                                      Amendments.  The Escrow Agreement is hereby amended as follows:

(a)                                 Amendment to Schedule 1.  Schedule 1 of the Escrow Agreement is hereby deleted in its entirety and replaced with Exhibit A attached hereto.

2.                                      Miscellaneous.

(a)                                 No Other Amendment.  Except as expressly amended in this Amendment, all provisions of the Escrow Agreement shall remain in full force and effect, and the parties thereto and hereto shall continue to have all their rights and remedies under the Escrow Agreement.  In the event of a conflict between the terms and provisions of this Amendment and the terms and provisions of the Escrow Agreement, the provisions of this Amendment shall govern.

(b)                                 Relation to Escrow Agreement.  This Amendment constitutes an integral part of the Escrow Agreement.  Upon the effectiveness of this Amendment, each reference in the

Escrow Agreement to “this Agreement,” “hereunder,” “hereof,” or words of like import referring to the Escrow Agreement, shall mean and be a reference to the Escrow Agreement as amended hereby.

(c)                                  Successors and Assigns.  This Amendment shall be binding on and shall inure to the benefit of the parties hereto and their respective successors and assigns except as otherwise provided herein.

(d)                                 Counterparts.  This Amendment may be executed by the parties hereto on any number of separate counterparts, any of which may be executed and transmitted by facsimile, and each of which shall be deemed an original and all of which, taken together, shall be deemed to constitute one and the same instrument.

(e)                                  Governing Law.  This Amendment shall be governed by, and construed in accordance with, the laws of the State of California, without regard to its principles of conflicts of law.

[Signature Page Follows]

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IN WITNESS WHEREOF, the parties hereto have caused this Amendment to be executed and delivered as of the date first above written.

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EXHIBIT A

Schedule 1

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