Classification: County
Located in: Illinois (IL)
Total Population (2000): 19704
Total Housing Units (2000): 8611
Land Area (square meters): 1614999349
Water Area (square meters): 1632124
Land Area (square miles): 623.554761
Water Area (square miles): 0.630167
Latitude (decimal degrees): 39.668118
Longitude (decimal degrees): -87.746849
FIPS Code: 17
Place FIPS Code: 45