Hamlin -- U.S. County in South Dakota Population (2000): 5540 Housing Units (2000): 2626 Land area (2000): 506.864464 sq. miles (1312.772879 sq. km) Water area (2000): 31.095304 sq. miles (80.536463 sq. km) Total area (2000): 537.959768 sq. miles (1393.309342 sq. km) Located within: South Dakota (SD), FIPS 46 Location: 44.666335 N, 97.178629 W Headwords: Hamlin Hamlin, SD Hamlin County Hamlin County, SD