Learn About
The Commemorative
Quarter for
The Commemorative Quarter for Wisconsin

Time Zone: Rock County lies in the Central Time Zone (CST/CDT) and observes daylight saving time.

The community of Janesville is the Seat for Rock County.

Rock County was founded in 1836.

From the Census Estimates for 2009, <1> Rock had a population of 160,155 people. This is an increase of 5.15% since the last Census (which gave a population of 152,307 people in 2000).

At the time of the 2000 Census, Rock represented 2.84% of the total population of Wisconsin, making it the state's 8th most populous county (out of 72 counties).

The following table shows the recent changes in population. Other than 2000, the population counts have been estimated by the Census Bureau.

Since 2000
Year-to-Year Change
2010160,331+5.27%+0.11% since 2009
2008160,186+5.17%+0.46% since 2007
2000152,307The Last Census

More information can be found on the Rock County Census Page for Rock County.


Below are some of the communities located in Rock County (for more communities, please visit our Nearby Page for Rock County):

Community 2009
(2009vs. 2000)
Janesville   63,32559,4986.43% increase  
Beloit   36,56035,7752.19% increase  
Beloit   7,4637,0386.04% increase  
Milton   5,7445,13211.93% increase  
Edgerton   5,3394,9338.23% increase  

Websites for Rock County

Official Website:   www.co.rock.wi.us/

If you know of a history or genealogy society whose interest includes Rock County, would you please send us the URL for their website? We would like to add their link to our Gazetteer. To contact us, please visit our Feedback Page.

Other Roadside Stops ...

About Wisconsin

Find a Community within Wisconsin

Footnotes ...

<1>On a yearly basis, the US Census Bureau creates an estimate of the county's population. Keep in mind that this is an estimate and not an actual count. The last physical count was the 2000 Census and the next count will be for the 2010 Census.

- Return to Citation

<2>All Quarter-dollar coin images from the United States Mint.

- Return to Citation