Tonica, IL -- U.S. village in Illinois Population (2000): 685 Housing Units (2000): 306 Land area (2000): 1.355105 sq. miles (3.509706 sq. km) Water area (2000): 0.000000 sq. miles (0.000000 sq. km) Total area (2000): 1.355105 sq. miles (3.509706 sq. km) FIPS code: 75718 Located within: Illinois (IL), FIPS 17 Location: 41.215902 N, 89.067981 W ZIP Codes (1990): 61370 Note: some ZIP codes may be omitted esp. for suburbs. Headwords: Tonica, IL Tonica