William C. Rusnack has been a director since 2001. He was the President and Chief Executive Officer and a director of Premcor, Inc from 1998 to 2002. Prior to 1998, he was an executive of Atlantic Richfield Company. He is also a director of Flowserve and Peabody. Energy. He is a member of the Dean's Advisory Council of the Graduate School of Business at the University of Chicago and the National Council of the Olin School of Business at the Washington University in St. Louis.