'St. Clair County, IL' definitions:
St. Clair -- U.S. County in Illinois
From: Gazetteer 2000
Name :
St. Clair -- U.S. County in Illinois
Population (2000) :
256082
Housing Units (2000) :
104446
Land area (2000) :
663.807610 sq. miles (1719.253745 sq. km)
Water area (2000) :
10.146000 sq. miles (26.278018 sq. km)
Total area (2000) :
673.953610 sq. miles (1745.531763 sq. km)
Located within :
Illinois (IL), FIPS 17
Location :
38.532682 N, 90.002067 W