Classification: County
Located in: Illinois (IL)
Total Population (2000): 128485
Total Housing Units (2000): 52973
Land Area (square meters): 1680540029
Water Area (square meters): 23393536
Land Area (square miles): 648.86016
Water Area (square miles): 9.032295
Latitude (decimal degrees): 40.557333
Longitude (decimal degrees): -89.540657
FIPS Code: 17
Place FIPS Code: 179