E laine Tettemer Marshall is an American billionaire who inherited her vast fortune from her late husband, E. Pierce Marshall. Her wealth is a complex legacy, with its roots in the oil fortune of her father-in-law, the legendary Texas oil tycoon J. Howard Marshall II. A significant portion of her wealth comes from a large stake in Koch Industries, the massive private industrial conglomerate.

J. Howard Marshall II was an early investor in the company that would become Koch Industries. This stake, which E. Pierce Marshall inherited and successfully defended in long and bitter legal battles against his brother and his father's young widow, Anna Nicole Smith, has grown to be worth billions. Upon her husband's death in 2006, Elaine inherited his 16% stake in Koch Industries. She now sits on the board of Koch Industries, overseeing her family's massive and valuable interest in the private industrial giant.