From 2009 to January 2011, Mr. Walker served as a Senior Vice President of Alpha Natural Resources, Inc., assisting with integration issues after the merger of Alpha Natural Resources, Inc. and Foundation Coal Holdings, Inc. From 2004 to 2009, Mr. Walker served as the Senior Vice President, General Counsel and Secretary of Foundation Coal Holdings, Inc. From 1999 to 2004, he served as the Senior Vice President, General Counsel and Secretary of RAG American Coal Holdings, Inc., which was the predecessor entity to Foundation Coal Holdings, Inc. From 1989 through 1999, he served in various capacities in the law department of Cyprus Amax Minerals Company. He spent three years in private law practice in Denver, Colorado from 1986 to 1989, and from 1981 through 1986 he held various positions within the law department of Mobil Oil Corporation. From 2005 through 2012 he was a member of the board of directors of the FutureGen Industrial Alliance, Inc., a not-for-profit entity whose global members are working with the United States Department of Energy to build and operate a commercial scale, oxy-combustion coal fired power plant with carbon dioxide capture and sequestration. He currently serves as the Treasurer and Secretary of FutureGen. From 2007 through 2010, he served as an appointee from the United States to the Coal Industry Advisory Board, an international advisory panel to the International Energy Administration with respect to matters regarding the production, use and demand for coal on a global basis.