Classification: County
Located in: Illinois (IL)
Total Population (2000): 41691
Total Housing Units (2000): 18022
Land Area (square meters): 1482156493
Water Area (square meters): 8912592
Land Area (square miles): 572.263846
Water Area (square miles): 3.441171
Latitude (decimal degrees): 38.614865
Longitude (decimal degrees): -88.993656
FIPS Code: 17
Place FIPS Code: 121