Oacoma, SD -- U.S. town in South Dakota Population (2000): 390 Housing Units (2000): 188 Land area (2000): 2.022935 sq. miles (5.239377 sq. km) Water area (2000): 2.422905 sq. miles (6.275294 sq. km) Total area (2000): 4.445840 sq. miles (11.514671 sq. km) FIPS code: 46180 Located within: South Dakota (SD), FIPS 46 Location: 43.804117 N, 99.380157 W ZIP Codes (1990): Note: some ZIP codes may be omitted esp. for suburbs. Headwords: Oacoma, SD Oacoma