63631 -- U.S. ZIP code Municipality (1990): CALEDONIA, Missouri All ZIPs for this municipality (1990): 63631 Population (2000): 953 Housing Units (2000): 420 Land area (2000): 43.461876 sq. miles (112.565738 sq. km) Water area (2000): 0.037169 sq. miles (0.096266 sq. km) Total area (2000): 43.499045 sq. miles (112.662004 sq. km) Located within: Missouri (MO) Location: 37.753408 N, 90.785930 W