Grant County, Wisconsin

Grant County
Grant County Courthouse, Armand D. Koch, architect, 1902
Location within the U.S. state of Wisconsin
Wisconsin's location within the U.S.
Coordinates: 42°52′N 90°43′W / 42.86°N 90.71°W / 42.86; -90.71
Country United States
State Wisconsin
Founded1837
SeatLancaster
Largest cityPlatteville
Area
  Total
1,183 sq mi (3,060 km2)
  Land1,147 sq mi (2,970 km2)
  Water36 sq mi (90 km2)  3.1%
Population
 (2020)
  Total
51,938
  Estimate 
(2024)
52,330
  Density45.6/sq mi (17.6/km2)
Time zoneUTC−6 (Central)
  Summer (DST)UTC−5 (CDT)
Congressional district3rd
Websitewww.co.grant.wi.gov

Grant County is the most southwestern county in the U.S. state of Wisconsin. As of the 2020 census, the population was 51,938. Its county seat is Lancaster and its largest city is Platteville. The county is named after the Grant River, in turn named after a fur trader who lived in the area when Wisconsin was a territory. Grant County comprises the Platteville Micropolitan Statistical Area. It is in the tri-state area of Wisconsin, Illinois, and Iowa, and is crossed by travelers commuting to Madison, Wisconsin, from a number of eastern Iowan cities, and by residents of northern Illinois traveling to the Twin Cities or La Crosse, Wisconsin.