63664 -- U.S. ZIP code Municipality (1990): POTOSI, Missouri All ZIPs for this municipality (1990): 63664 Population (2000): 8525 Housing Units (2000): 3676 Land area (2000): 288.143911 sq. miles (746.289271 sq. km) Water area (2000): 1.057259 sq. miles (2.738289 sq. km) Total area (2000): 289.201170 sq. miles (749.027560 sq. km) Located within: Missouri (MO) Location: 37.914960 N, 90.867978 W