Plains, MT -- U.S. town in Montana Population (2000): 1126 Housing Units (2000): 532 Land area (2000): 0.561518 sq. miles (1.454325 sq. km) Water area (2000): 0.000000 sq. miles (0.000000 sq. km) Total area (2000): 0.561518 sq. miles (1.454325 sq. km) FIPS code: 58150 Located within: Montana (MT), FIPS 30 Location: 47.458504 N, 114.885024 W ZIP Codes (1990): 59859 Note: some ZIP codes may be omitted esp. for suburbs. Headwords: Plains, MT Plains