Brown -- U.S. County in South Dakota Population (2000): 35460 Housing Units (2000): 15861 Land area (2000): 1713.069884 sq. miles (4436.830444 sq. km) Water area (2000): 18.138538 sq. miles (46.978597 sq. km) Total area (2000): 1731.208422 sq. miles (4483.809041 sq. km) Located within: South Dakota (SD), FIPS 46 Location: 45.538665 N, 98.381992 W Headwords: Brown Brown, SD Brown County Brown County, SD