63012 -- U.S. ZIP code Municipality (1990): BARNHART, Missouri All ZIPs for this municipality (1990): 63012 Population (2000): 9367 Housing Units (2000): 3162 Land area (2000): 27.228230 sq. miles (70.520788 sq. km) Water area (2000): 0.011197 sq. miles (0.028999 sq. km) Total area (2000): 27.239427 sq. miles (70.549787 sq. km) Located within: Missouri (MO) Location: 38.337458 N, 90.423169 W