UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

SCHEDULE 14A

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Stillwater Mining Company

(Name of Registrant as Specified In Its Charter)

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  PRESS RELEASE  

FOR IMMEDIATE RELEASE:                 MAY 2, 2013

STILLWATER RESPONDS TO CLINTON GROUP’S RECENT PRESS RELEASE

BILLINGS, MONTANA – Stillwater Mining Company (NYSE:SWC) (TSX:SWC.U) (“Stillwater” or the “Company”) today responded to a press release issued by the Clinton Group, Inc. (“Clinton Group”), a 1.3% shareholder, in advance of today’s 2013 Annual Shareholders Meeting set for May 2, 2013.

Patrick M. James, Stillwater’s lead independent director, said, “Clinton Group’s press release is an unfortunate attack that is without merit and the annual meeting will proceed later today as planned. Our annual meeting was scheduled long ago and set at our premier mine location to show shareholders the tremendous progress we have made. Regardless of the outcome at today’s annual meeting, we are certain that the new Board will be committed to maintaining the positive momentum that the Company and its employees have achieved, particularly at our core Montana operations. Our director nominees are ready to be part of a newly elected Board that will work to realize, for shareholders, the Company’s full potential and continue the recent operational and financial achievements, as evidenced by our first quarter earnings results.”

All shareholders of record as of March 6, 2013 are entitled to vote at the 2013 Annual Shareholders Meeting on May 2, 2013. Stillwater continues to encourage all shareholders to vote only their WHITE proxy card. For more information about Stillwater’s 2013 Annual Shareholders Meeting, please visit www.supportstillwater.com.

About Stillwater Mining Company

Stillwater Mining Company is the only U.S. producer of palladium and platinum and is the largest primary producer of platinum group metals outside of South Africa and the Russian Federation. The Company’s shares are traded on the New York Stock Exchange under the symbol SWC and on the Toronto Stock Exchange under the symbol SWC.U. Information on Stillwater Mining Company can be found at its website: www.stillwatermining.com.

Some statements contained in this news release are forward-looking statements within the meaning of Section 27A of the Securities Act of 1933, as amended, and Section 21E of the Securities Exchange Act of 1934, as amended, and, therefore, involve uncertainties or risks that could cause actual results to differ materially. These statements may contain words such as “believes,” “anticipates,” “plans,” “expects,” “intends,” “projects”, “estimates,” “forecast,” “guidance,” or similar expressions. These statements are not guarantees of the Company’s future performance and are subject to risks, uncertainties and other important factors that could cause our actual performance or achievements to differ materially from those expressed or implied by these forward-looking statements. Such statements include, but are not limited to, comments

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regarding expansion plans, costs, grade, production and recovery rates, permitting, financing needs, the terms of future credit facilities and capital expenditures, increases in processing capacity, cost reduction measures, safety, timing for engineering studies, and environmental permitting and compliance, litigation, labor matters and the palladium and platinum market. Additional information regarding factors, which could cause results to differ materially from management’s expectations, is found in the section entitled “Risk Factors” in the Company’s 2012 Annual Report on Form 10-K and in subsequent filings with the United States Securities & Exchange Commission. The Company intends that the forward-looking statements contained herein be subject to the above-mentioned statutory safe harbors. Investors are cautioned not to rely on forward-looking statements. The Company disclaims any obligation to update forward-looking statements.

INVESTOR CONTACTS

Mike Beckstead

(406) 373-8971

Or

Arthur Crozier / Jennifer Shotwell / Scott Winter

Innisfree M&A Incorporated

(212) 750-5833

MEDIA CONTACTS:

Dan Gagnier / Michael Henson

Sard Verbinnen & Co

(212) 687-8080

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