Classification: County
Located in: Illinois (IL)
Total Population (2000): 179669
Total Housing Units (2000): 75280
Land Area (square meters): 2581715418
Water Area (square meters): 1881148
Land Area (square miles): 996.805938
Water Area (square miles): 0.726315
Latitude (decimal degrees): 40.136824
Longitude (decimal degrees): -88.216752
FIPS Code: 17
Place FIPS Code: 19