Sullivan -- U.S. County in Indiana Population (2000): 21751 Housing Units (2000): 8804 Land area (2000): 447.195796 sq. miles (1158.231746 sq. km) Water area (2000): 6.845894 sq. miles (17.730783 sq. km) Total area (2000): 454.041690 sq. miles (1175.962529 sq. km) Located within: Indiana (IN), FIPS 18 Location: 39.100806 N, 87.395420 W Headwords: Sullivan Sullivan, IN Sullivan County Sullivan County, IN