Humboldt, SD -- U.S. town in South Dakota Population (2000): 521 Housing Units (2000): 210 Land area (2000): 0.626957 sq. miles (1.623812 sq. km) Water area (2000): 0.000724 sq. miles (0.001874 sq. km) Total area (2000): 0.627681 sq. miles (1.625686 sq. km) FIPS code: 30900 Located within: South Dakota (SD), FIPS 46 Location: 43.644933 N, 97.074320 W ZIP Codes (1990): 57035 Note: some ZIP codes may be omitted esp. for suburbs. Headwords: Humboldt, SD Humboldt