Classification: County
Located in: Illinois (IL)
Total Population (2000): 31183
Total Housing Units (2000): 11872
Land Area (square meters): 1600974150
Water Area (square meters): 2242885
Land Area (square miles): 618.139601
Water Area (square miles): 0.865983
Latitude (decimal degrees): 40.143596
Longitude (decimal degrees): -89.365106
FIPS Code: 17
Place FIPS Code: 107