Sully -- U.S. County in South Dakota Population (2000): 1556 Housing Units (2000): 844 Land area (2000): 1006.899280 sq. miles (2607.857052 sq. km) Water area (2000): 63.460182 sq. miles (164.361110 sq. km) Total area (2000): 1070.359462 sq. miles (2772.218162 sq. km) Located within: South Dakota (SD), FIPS 46 Location: 44.714843 N, 100.090532 W Headwords: Sully Sully, SD Sully County Sully County, SD