35601 -- U.S. ZIP code Municipality (1990): DECATUR, Alabama All ZIPs for this municipality (1990): 35601 35603 Population (2000): 34859 Housing Units (2000): 15478 Land area (2000): 26.462035 sq. miles (68.536354 sq. km) Water area (2000): 0.087063 sq. miles (0.225491 sq. km) Total area (2000): 26.549098 sq. miles (68.761845 sq. km) Located within: Alabama (AL) Location: 34.595332 N, 86.987863 W