63866 -- U.S. ZIP code Municipality (1990): MARSTON, Missouri All ZIPs for this municipality (1990): 63866 Population (2000): 658 Housing Units (2000): 323 Land area (2000): 5.154708 sq. miles (13.350632 sq. km) Water area (2000): 0.011624 sq. miles (0.030107 sq. km) Total area (2000): 5.166332 sq. miles (13.380739 sq. km) Located within: Missouri (MO) Location: 36.521724 N, 89.607305 W