2010 Top 200 U.S. CEOs

Biography
Mr. Boyce, age 55, has been a director since March 2005. Mr. Boyce was named Chief Executive Officer Elect of the Company in March 2005, assumed the position of Chief Executive Officer in January 2006 and was elected Chairman by the Board of Directors in October 2007. He was President of the Company from October 2003 to December 2007 and was Chief Operating Officer of the Company from October 2003 to December 2005. He previously served as Chief Executive - Energy of Rio Tinto plc (an international natural resource company) from 2000 to 2003. Other prior positions include President and Chief Executive Officer of Kennecott Energy Company from 1994 to 1999 and President of Kennecott Minerals Company from 1993 to 1994. He has extensive engineering and operating experience with Kennecott and also served as Executive Assistant to the Vice Chairman of Standard Oil of Ohio from 1983 to 1984. Mr. Boyce serves on the board of directors of Marathon Oil Corporation. He is Vice Chairman of the World Coal Institute and the National Mining Association. He is a member of the National Coal Council (NCC) and the Coal Industry Advisory Board of the International Energy Agency. He is a Board member of the Business Roundtable and the American Coalition for Clean Coal Electricity (ACCCE). Mr. Boyce is a member of Civic Progress in St. Louis; the Board of Trustees of St. Louis Children's Hospital; the Board of Trustees of Washington University in St. Louis; the School of Engineering and Applied Science National Council at Washington University in St. Louis; and the Advisory Council of the University of Arizona's Department of Mining and Geological Engineering. Mr. Boyce's extensive experience in the global energy and mining industries, combined with his drive for innovation and excellence, make him highly qualified to serve as our Chairman and Chief Executive Officer.