61259 -- U.S. ZIP code Municipality (1990): ILLINOIS CITY, Illinois All ZIPs for this municipality (1990): 61259 Population (2000): 1209 Housing Units (2000): 471 Land area (2000): 61.147334 sq. miles (158.370861 sq. km) Water area (2000): 0.376381 sq. miles (0.974823 sq. km) Total area (2000): 61.523715 sq. miles (159.345684 sq. km) Located within: Illinois (IL) Location: 41.369036 N, 90.928405 W