64646 -- U.S. ZIP code Municipality (1990): HUMPHREYS, Missouri All ZIPs for this municipality (1990): 64646 Population (2000): 385 Housing Units (2000): 174 Land area (2000): 56.056120 sq. miles (145.184677 sq. km) Water area (2000): 0.016915 sq. miles (0.043810 sq. km) Total area (2000): 56.073035 sq. miles (145.228487 sq. km) Located within: Missouri (MO) Location: 40.115577 N, 93.314895 W