'Jefferson County, WI' definitions:

Jefferson -- U.S. County in Wisconsin

From: Gazetteer 2000
Name :
Jefferson -- U.S. County in Wisconsin
Population (2000) :
74021
Housing Units (2000) :
30092
Land area (2000) :
557.014036 sq. miles (1442.659668 sq. km)
Water area (2000) :
25.732932 sq. miles (66.647984 sq. km)
Total area (2000) :
582.746968 sq. miles (1509.307652 sq. km)
Located within :
Wisconsin (WI), FIPS 55
Location :
43.043142 N, 88.783670 W