'Jasper County, IL' definitions:

Jasper -- U.S. County in Illinois

From: Gazetteer 2000
Name :
Jasper -- U.S. County in Illinois
Population (2000) :
10117
Housing Units (2000) :
4294
Land area (2000) :
494.403808 sq. miles (1280.499931 sq. km)
Water area (2000) :
3.615607 sq. miles (9.364378 sq. km)
Total area (2000) :
498.019415 sq. miles (1289.864309 sq. km)
Located within :
Illinois (IL), FIPS 17
Location :
39.009625 N, 88.140296 W