United States Antimony Corporation或者USAC,於1970年1月成立於蒙大拿州，致力於開採並生產銻產品。1983年，它停止了銻開採業務但繼續從國內和國外原料基地生產銻產品。1998年3月，該公司成立了United States Antimony SA de CV 或 USAMSA，在墨西哥開採和冶鍊銻。Bear River Zeolite公司成立於2000年，在愛達荷州東南地區開採並生產沸石。2005年8月19號，United States Antimony成立了Antimonio de Mexico，S. A. de C. V.，在墨西哥探索並開發銻及銀礦，Antimonio de Mexico，S. A. de C. V.現在併入了USAMSA。該公司主要的業務就是生產和銷售銻、銀、金和沸石產品。
董事
名稱
職位
Gary C. Evans
Chairman of the Board and Chief Executive Officer
Blaise Aguirre
Independent Director
John M. Keane
Independent Director
Joseph A. Carrabba
Independent Director
Joseph Bardswich
Director, Executive Vice President and Chief Mining Engineer
Michael A. Mcmanus, Jr
Independent Director
股東
名稱
職位
Gary C. Evans
Chairman of the Board and Chief Executive Officer
Melissa M. Pagen
Senior Vice President, Corporate Development and Governmental Relations
Richard R. Isaak
Senior Vice President, Chief Financial Officer and Principal Accounting Officer
Jeffrey Fink
Vice President and General Manager, Bear River Zeolite
John C. Gustavsen
President, Antimony Division
Joseph Bardswich
Director, Executive Vice President and Chief Mining Engineer