Classification: County
Located in: Illinois (IL)
Total Population (2000): 40045
Total Housing Units (2000): 16990
Land Area (square meters): 1478768461
Water Area (square meters): 33040991
Land Area (square miles): 570.955719
Water Area (square miles): 12.757198
Latitude (decimal degrees): 38.310378
Longitude (decimal degrees): -88.915252
FIPS Code: 17
Place FIPS Code: 81