Dewey -- U.S. County in South Dakota Population (2000): 5972 Housing Units (2000): 2133 Land area (2000): 2302.643442 sq. miles (5963.818882 sq. km) Water area (2000): 143.028378 sq. miles (370.441783 sq. km) Total area (2000): 2445.671820 sq. miles (6334.260665 sq. km) Located within: South Dakota (SD), FIPS 46 Location: 45.213613 N, 101.003656 W Headwords: Dewey Dewey, SD Dewey County Dewey County, SD