Riverstone Gives Notice of Exercise of Option Agreement to Golden Star Resources Inc.

VANCOUVER, BRITISH COLUMBIA -- (Marketwire) -- 12/23/11 -- Riverstone Resources Inc. (TSX VENTURE: RVS)(OTCQX: RVREF)(FRANKFURT: 3RV) ('Riverstone' or the 'Company') announces that it has given notice to Golden Star Resources Inc. ('Golden Star') that Riverstone will exercise the option (the 'Option') to acquire (the 'Acquisition') an indirect 90% interest in the Goulagou, Rounga, Tougou and Youba permits located in Burkina Faso, West Africa (collectively, the 'Properties'). The Acquisition is expected to be completed on or before January 27, 2012.

Riverstone acquired the Option pursuant to the terms of a letter agreement with Golden Star dated October 10, 2007 (subsequently supplemented by addenda agreements, and referred to collectively as the 'Agreement'). To maintain and exercise the Option under the terms of the Agreement, the Company has issued to Golden Star an aggregate of 2,000,000 common shares and an additional 2,000,000 share purchase warrants, and has incurred an aggregate of $5.9 M in exploration expenditures on the Properties.

On the closing of the Acquisition, Riverstone will pay to Golden Star the sum of US$18.6 million (the 'Purchase Price'), which amount is payable, at the election of the Company, in cash, shares, or a combination of cash and shares. If the Company elects to satisfy the Purchase Price in part through the issuance of common shares, the issue price of such shares would be based on the 20 day volume-weighted average price of the Company common shares for the 20 day period ended on December 20, 2011.

Golden Star will retain a net smelter returns royalty of between 0% and 2% depending on the quantity of gold produced from the Properties. Golden Star also retains a right of first offer on the Properties should Riverstone intend to sell or transfer all or any part thereof. If Golden Star does not elect within a prescribed period of time to purchase the Properties offered on the terms then proposed by Riverstone, Riverstone would have the right, for a period of 120 days thereafter, to sell the Properties to a third party on substantially similar terms.

On the closing of the Acquisition, Riverstone will also acquire the right to increase its interest in the Properties to 100% by paying to a third party the sum of US$1,000,000 on or before 12 months after the first production of gold from the Properties. Thereafter, the third party will retain a 5% net profits interest, which can be purchased by the Company for the sum of US$500,000.

The Properties form part of the Company's Karma Project which comprises six contiguous permits. The Company has a 100% interest in two of the permits and has an option to acquire an indirect 90% interest in the Properties to be acquired from Golden Star by completion of the Acquisition. The Karma Project has a NI 43-101 compliant gold resource of 810,600 ounces of gold in 22,845,000 tonnes grading 1.10 g/t gold in the indicated category and 1,119,100 ounces of gold in 44,100,000 tonnes grading 0.79 g/t gold in the inferred category. (See the Company's news release of February 28, 2011). Since the resource was calculated in February 2011, the Company has drilled in excess of an additional 40,000 metres at Karma, and it is expected that the results of this drilling will add to the resource.

ON BEHALF OF THE BOARD

Michael D. McInnis, P. Eng., Chairman & CEO

Certain statements made and information contained in this news release and elsewhere constitutes 'forward-looking information' within the meaning of the Ontario Securities Act. Forward-looking statements are subject to a variety of risks and uncertainties which could cause actual events or results to differ from those reflected in the forward-looking statements, including, without limitation, risks and uncertainties relating to the interpretation of drill results and the estimation of mineral resources, the geology, grade and continuity of mineral deposits, the possibility that future exploration, development results will not be consistent with the Company's expectations, accidents, equipment breakdowns, title matters and surface access, labour disputes, the potential for delays in exploration activities, the potential for unexpected costs and expenses, commodity price fluctuations, currency fluctuations, failure to obtain adequate financing on a timely basis and other risks and uncertainties, including those described under Risk Factors in each management discussion and analysis. In addition, forward-looking information is based on various assumptions including, without limitation, the expectations and beliefs of management, the assumed long term price of gold, that the Company will receive required permits and access to surface rights, that the Company can access financing, appropriate equipment and sufficient labour and that the political environment within Burkina Faso will continue to support the development of environmentally safe mining projects. Should one or more of these risks and uncertainties materialize, or should underlying assumptions prove incorrect, actual results may vary materially from those described in forward-looking statements. Accordingly, readers are advised not to place undue reliance on forward-looking statements.

Neither TSX Venture Exchange nor its Regulation Services Provider (as that term is defined in the policies of the TSX Venture Exchange) accepts responsibility for the adequacy or accuracy of this release.

Contacts:

Riverstone Resources Inc. - Vancouver Office

Dwayne L. Melrose

President

604-801-5020
info@riverstoneresources.com


Riverstone Resources Inc. - Vancouver Office

Don Mosher

Corporate Development

604-685-6465


Riverstone Resources Inc.

Raju Wani

Investor Relations

403-240-0555


Riverstone Resources Inc. - Vancouver Office

Ron Cooper

Investor Relations

604-986-0112
www.riverstoneresources.com