Clark -- U.S. County in South Dakota Population (2000): 4143 Housing Units (2000): 1880 Land area (2000): 957.923996 sq. miles (2481.011655 sq. km) Water area (2000): 9.865736 sq. miles (25.552139 sq. km) Total area (2000): 967.789732 sq. miles (2506.563794 sq. km) Located within: South Dakota (SD), FIPS 46 Location: 44.853152 N, 97.725341 W Headwords: Clark Clark, SD Clark County Clark County, SD