Armstrong, MO -- U.S. city in Missouri Population (2000): 287 Housing Units (2000): 142 Land area (2000): 0.842948 sq. miles (2.183226 sq. km) Water area (2000): 0.000000 sq. miles (0.000000 sq. km) Total area (2000): 0.842948 sq. miles (2.183226 sq. km) FIPS code: 01954 Located within: Missouri (MO), FIPS 29 Location: 39.268832 N, 92.700938 W ZIP Codes (1990): 65230 Note: some ZIP codes may be omitted esp. for suburbs. Headwords: Armstrong, MO Armstrong