Rock County is a county in the U.S. state of Wisconsin. As of the 2020 census, the population was 163,687. Rock County comprises the Janesville–Beloit metropolitan statistical area and is included in the Madison–Janesville–Beloit combined statistical area.

History

Rock County was created as a territorial county on December 7, 1836, from Milwaukee County and fully organized February 19, 1839. The county is named for the Rock River, which bisects the county from north to south.

Geography

According to the U.S. Census Bureau, the county has a total area of , of which is land and (1.1%) is water.

Cook Memorial Arboretum, a natural area with birding and nature trails, is located northwest of Janesville. It is owned by the Janesville School District.

Transportation

Major highways

  • 20px Interstate 39
  • 20px Interstate 43
  • 20px Interstate 90
  • 20px U.S. Highway 12
  • 20px U.S. Highway 14
  • 20px U.S. Highway 51
  • 20px Highway 11
  • 20px Highway 26
  • 20px Highway 59
  • 20px Highway 67
  • 20px Highway 81
  • 20px Highway 89
  • 20px Highway 104
  • 20px Highway 138
  • 20px Highway 140
  • 20px Highway 213

Railroads

  • Canadian Pacific
  • Union Pacific
  • Wisconsin and Southern Railroad

Buses

  • Beloit Transit
  • Janesville Transit System

Airport

Southern Wisconsin Regional Airport (KJVL) serves Rock County and the surrounding communities.

Adjacent counties

  • Green County – west
  • Dane County – north
  • Jefferson County – northeast
  • Walworth County – east
  • Boone County, Illinois – south
  • Winnebago County, Illinois – south

Demographics

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Since 1988, Rock County has consistently voted for the Democratic candidate in every Presidential election. In 2024, Kamala Harris carried the county by the smallest margin of victory since Michael Dukakis in 1988.

Education

School districts include:

  • Albany School District
  • School District of Beloit
  • Beloit Turner School District
  • Brodhead School District
  • Clinton Community School District
  • Delavan-Darien School District
  • Edgerton School District
  • Evansville Community School District
  • Fort Atkinson School District
  • School District of Janesville
  • Milton School District
  • Oregon School District
  • Parkview School District
  • Stoughton Area School District
  • Whitewater School District

There is a state-operated school, Wisconsin School for the Blind and Visually Impaired.

See also

  • National Register of Historic Places listings in Rock County, Wisconsin

References

Further reading

  • Brown, William F. Rock County, Wisconsin: A New History... Vol. 1, Chicago: Cooper, 1908.
  • Brown, William F. Rock County, Wisconsin: A New History... Vol. 2, Chicago: Cooper, 1908.
  • Commemorative Biographical Record of the Counties of Rock, Green, Grant, Iowa, and Lafayette, Wisconsin, Containing Biographical Sketches of Prominent and Representative Citizens, and of Many of the Early Settled Families. Chicago: J. H. Beers and Co., 1901.
  • The History of Rock County, Wisconsin. Chicago: Western Historical Company, 1879.
  • Portrait and Biographical Album of Rock County, Wisconsin. Chicago: Acme Publishing Company, 1889.
  • Sayre, David F. "Early Life in Southern Wisconsin", Wisconsin Magazine of History, vol. 3, no. 4 (June 1920), pp.&nbsp;420–427.
  • Smith, Isaac T. "Early Settlement of Rock County" in Wisconsin Historical Collections, vol. VI. Madison, Wis.: Atwood & Culver, 1872, pp.&nbsp;416–425.
  • Walterman, Thomas. There Stands "Old Rock": Rock County, Wisconsin and the War to Preserve the Union. Friendship, Wis.: New Past Press, 2001.
  • Rock County government website
  • Rock County map from the Wisconsin Department of Transportation
  • Rock County 5.0
  • Rock County Historical Society
  • Rock County Genealogical Society
  • Beloit Janesville Symphony