Martha A Burger

Martha A. Burger has served as Senior Vice President – Human and Corporate Resources since March 2007. Ms. Burger’s prior positions with the Company included the following: Treasurer from 1995 to March 2007, Senior Vice President – Human Resources from 2000 to March 2007, Vice President – Human Resources from 1998 to 2000, Human Resources Manager from 1996 to 1998, Corporate Secretary from 1999 to 2000, and various accounting positions with the Company, including Assistant Controller – Operations, from 1994 to 1995. Ms. Burger was employed by Hadson Corporation as Assistant Treasurer from 1989 to 1993 and served as Vice President and Controller of Hadson Corporation from 1993 to 1994. Prior to joining Hadson Corporation, Ms. Burger was employed by The Phoenix Resource Companies, Inc. as Assistant Treasurer and by Arthur Andersen & Co. Ms. Burger graduated from the University of Central Oklahoma in 1982 and from Oklahoma City University in 1992.