Westport, SD -- U.S. town in South Dakota Population (2000): 125 Housing Units (2000): 52 Land area (2000): 0.260567 sq. miles (0.674865 sq. km) Water area (2000): 0.000000 sq. miles (0.000000 sq. km) Total area (2000): 0.260567 sq. miles (0.674865 sq. km) FIPS code: 70540 Located within: South Dakota (SD), FIPS 46 Location: 45.648875 N, 98.497262 W ZIP Codes (1990): Note: some ZIP codes may be omitted esp. for suburbs. Headwords: Westport, SD Westport