Rock County, Wisconsin


Rock County is a county in the U.S. state of Wisconsin. As of the 2010 census, the population was 160,331. Its county seat is Janesville.
Rock County comprises the Janesville-Beloit, WI Metropolitan Statistical Area and is included in the Madison-Janesville-Beloit, WI Combined Statistical Area.

History

Rock County was created in 1836 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 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

serves Rock County and the surrounding communities.

Adjacent counties

As of the census of 2000, there were 152,307 people, 58,617 households, and 40,387 families residing in the county. The population density was 211 people per square mile. There were 62,187 housing units at an average density of 86 per square mile. The racial makeup of the county was 91.01% white, 4.63% black or African American, 0.28% Native American, 0.78% Asian, 0.04% Pacific Islander, 1.77% from other races, and 1.50% from two or more races. 3.91% of the population were Hispanic or Latino of any race. 32.8% were of German, 13.0% Norwegian, 10.1% Irish, 7.5% English and 5.5% American ancestry.
There were 58,617 households out of which 33.60% had children under the age of 18 living with them, 53.50% were married couples living together, 10.90% had a female householder with no husband present, and 31.10% were non-families. 25.10% of all households were made up of individuals and 9.70% had someone living alone who was 65 years of age or older. The average household size was 2.54 and the average family size was 3.03.
In the county, the population was spread out with 26.50% under the age of 18, 8.60% from 18 to 24, 29.80% from 25 to 44, 22.30% from 45 to 64, and 12.70% who were 65 years of age or older. The median age was 36 years. For every 100 females there were 97.00 males. For every 100 females age 18 and over, there were 94.10 males.

Communities

Cities

carried the county in 2016, but it was the smallest margin of victory since Michael Dukakis in 1988.

Tree cities