Denison, IA -- U.S. city in Iowa Population (2000): 7339 Housing Units (2000): 2837 Land area (2000): 6.190798 sq. miles (16.034093 sq. km) Water area (2000): 0.032901 sq. miles (0.085214 sq. km) Total area (2000): 6.223699 sq. miles (16.119307 sq. km) FIPS code: 19945 Located within: Iowa (IA), FIPS 19 Location: 42.017187 N, 95.351124 W ZIP Codes (1990): 51442 Note: some ZIP codes may be omitted esp. for suburbs. Headwords: Denison, IA Denison