KCS Energy Inc. was acquired by Petrohawk Energy Corporation in July 2006. KCS Energy, Inc., was an independent energy company, engaged in the acquisition, exploration, development, and production of natural gas and crude oil. Its properties were primarily located in the mid-Continent and onshore Gulf Coast regions of the United States. The company also had interests in producing properties in Michigan, California, Wyoming, and offshore Gulf of Mexico. Its properties in mid-Continent included Elm Grove/Caspiana fields in Bossier Parish of north Louisiana; Terryville field in Lincoln Parish, Louisiana; Sawyer Canyon field in Sutton County, west Texas; and Joaquin field in Louisiana border in Shelby County. The company's properties in Gulf Coast regions comprised O'Connor Ranch field, the West Mission Valley, Coquat field, Austin Deep field, and La Reforma field.