Population (2020)163,687 (2020)
Neighborhood History and Places to Discover
Rock County, WisconsinStart exploring Rock County, Wisconsin, from its county seat in Janesville. This guide brings together local history, county facts, and links to the public services that help you plan a visit or settle into everyday life. Discover historic places such as Courthouse Hill Historic District, browse photographs from the county's National Register listings, and find official resources for parks, libraries, schools, transportation, and more.
Rock County at a Glance
Population (2020)163,687 (2020)
County SeatJanesville
Largest Municipality¹Janesville city
Created (Effective)07 Dec 1836
Municipalities¹29
Total Area²726.2 sq mi
Major HighwaysI-39, I-43, I-90 • US 12, 14, 51 • WIS 11, 26, 59, 67, 81, 89, 104, 138, 140, 213
Office Area Code608
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Meet Local Businesses
Support the businesses that help make our communities thrive. From family-owned shops and restaurants to trusted local services, discover businesses worth visiting throughout the county.
Discover the County
Rock County
The history of Rock County can be explored through its civic buildings, neighborhoods, and other registered landmarks. Courthouse Hill Historic District is one place to begin. The county's National Register listings also include Bartlett Memorial Historical Museum. Together, these places offer different ways to look at the communities that make up the county. Janesville is the county seat, while the Newberry Library's county chronology records 07 Dec 1836 as the effective creation date. Use the linked historic-place list to explore individual entries and their source records.
Everyday life extends across communities including Janesville city, Beloit city, Beloit town, Edgerton city. The 2020 Census counted 163,687 residents in Rock County, with Janesville city its largest municipality by population within the county. Its total area of 726.2 square miles includes both land and water. Whether you are looking for a county office, planning time outdoors, or researching a place in the photographs, the resources below connect you with official information and practical next steps.
What Connects Us
Local Heritage
Explore Courthouse Hill Historic District and other registered places through the county's historic-place listings. Each entry connects a local landmark with its documented history.
Community Connections
Begin with Janesville, the county seat, and explore the towns, villages, and cities that make up Rock County. County government provides a starting point for public services.
Useful Resources
Find official links for parks, education, transportation, libraries, and public services. Check the responsible agency for current hours, requirements, and access before making plans.
Many Communities, Shared Stories, and Places to Explore
Places Across Wisconsin
Rock County in Pictures
12 Local Views • Our County Stories
Wisconsin Public Radio
Madison rally aims to support survivors of sexual assault, demand changes to prevent violence
A rally scheduled for Friday evening aims to allow sexual assault survivors to share their stories and demand…
Read the Story Oct 14, 2026 • 2 min read
Rock County & Wisconsin News
County and regional reporting first, with statewide headlines when more stories are needed.
Madison rally aims to support survivors of sexual assault, demand changes to prevent violence
A rally scheduled for Friday evening aims to allow sexual assault survivors to share their stories and demand…
Oct 14, 2026 • 2 min read
How Medicare experts are guiding Wisconsin patients through this year’s open enrollment
Some people in Wisconsin will be forced to change their Medicare Advantage plans, with some companies cutting back.…
Oct 14, 2026 • 2 min read
Tom Tiffany plane crash caused by pilot error, report finds
The National Transportation Safety Board investigated the loss of power onboard a small plane that Tiffany was aboard…
Oct 14, 2026 • 2 min read
Book details Wisconsin flight nurse’s role in critical WWII air missions
A new book follows a team of flight nurses and how they aided U.S. troops in surviving some…
Oct 14, 2026 • 2 min read
5 adults, 1 child dead in small plane crash near Wisconsin Dells
Five adults and one child are reportedly dead after a small plane crashed in Sauk County. The post…
Oct 14, 2026 • 2 min read
Shop - Dine - Discover
Meet Local Businesses
Support the businesses that help make our communities thrive. From family-owned shops and restaurants to trusted local services, discover businesses worth visiting throughout the county.
Public Resources
Useful Links for Rock County
Find county, state, and federal resources in one place. County links appear alongside clearly named statewide services. For current hours, locations, and requirements, follow the responsible agency’s website.
¹ Municipality counts and largest-place ranking use 2020 Census county subdivisions, including only the portion within this county. ² Total area includes land and water.
Government
COUNTY & LOCAL RESOURCES
Rock County Government
Official county government, departments, and resident services.
Phone 608-757-5660
Schools
COUNTY & LOCAL RESOURCES
Wisconsin Department of Public Instruction
Public education and school information.
Wisconsin Technical College System
Technical colleges, programs, and training options.
UW–Madison Extension
Community education, youth development, and county Extension offices.
Hospitals
COUNTY & LOCAL RESOURCES
Wisconsin Hospital Directory
Find licensed hospitals and official facility information.
Wisconsin Department of Health Services
Public health programs and health-service information.
Public Safety
COUNTY & LOCAL RESOURCES
Emergency Services
COUNTY & LOCAL RESOURCES
State Parks
COUNTY & LOCAL RESOURCES
State Park Camping Rules
Check camping requirements before planning an overnight stay.
Trails
COUNTY & LOCAL RESOURCES
North Country National Scenic Trail
Explore the national trail's Wisconsin connections and plan a visit.
Utilities
COUNTY & LOCAL RESOURCES
Wisconsin Public Service Commission
State utility regulation and consumer information.
Utility Assistance Programs
Find information about utility payment and access assistance.
Wisconsin Broadband Maps
Explore internet availability and broadband planning data.
Libraries
COUNTY & LOCAL RESOURCES
Wisconsin's Digital Library
Find digital books and audiobooks through participating libraries.
Courts
COUNTY & LOCAL RESOURCES
Wisconsin State Law Library
Find legal research materials and help locating information.
DMV
COUNTY & LOCAL RESOURCES
Vehicle Information for New Residents
Official vehicle title and registration guidance for new residents.
Transportation
COUNTY & LOCAL RESOURCES
Wisconsin Department of Transportation
State transportation programs, travel information, and project updates.
Postal Services
COUNTY & LOCAL RESOURCES
Veterans
COUNTY & LOCAL RESOURCES
Wisconsin Department of Veterans Affairs
State veterans benefits, programs, and services.
County and Tribal Veterans Service Officers
Locate an officer serving your county or tribal community.
U.S. Department of Veterans Affairs
Federal benefits and services for veterans and their families.
Employment
COUNTY & LOCAL RESOURCES
Wisconsin Department of Workforce Development
Employment services, worker information, and workforce programs.
Vocational Rehabilitation
Employment support information for people with disabilities.
Find the Information You Need
Practical starting points for visitors and residents.
Helpful Information
Questions About Rock County
County facts, historic places, public services, and planning information.
The county’s National Register list includes Courthouse Hill Historic District, Bartlett Memorial Historical Museum and Benton Avenue Historic District. Browse the county historic-place listings for photographs and source records. Listing on the register does not itself mean a property is open to visitors; check access with its owner or managing organization.
Janesville is the county seat. Start at Rock County Government for departments, public meetings, and office contact information.
Janesville city, Beloit city, Beloit town, Edgerton city are among its municipalities. The 2020 Census county-subdivision records list 29 municipalities or municipal portions within the county. View Census municipal data.
Rock County had 163,687 residents in the 2020 Census. That is a census count, rather than a current-year population estimate. View the Census county table.
Start with parks and recreation information and the Wisconsin DNR trail directory. Review each property’s location, access, seasonal conditions, and permitted activities before visiting.
Use the Wisconsin Department of Public Instruction and its school and district report cards. Confirm enrollment boundaries directly with the school district for your address.
The Wisconsin DHS hospital directory is an official starting point for finding hospitals. The Hospitals resource tab also links to public health and provider directories.
The main county number listed by the Wisconsin Counties Association is 608-757-5660. Visit Rock County Government to confirm the department, location, and office hours for your request.
ZIP Codes follow postal delivery routes and can cross municipal or county boundaries. Use USPS ZIP Code Lookup with a complete mailing address, or USPS Locations to find a post office.
Use 511 Wisconsin for roadway conditions and the National Weather Service for official forecasts and warnings. Check the conditions for your actual route and destination.
Photographs are documented through Wikipedia and Wikimedia Commons, with photographers, original file pages, and licenses listed on the Picture Attribution page. News combines county or regional reporting where available with Wisconsin-wide coverage. Open a story to read the full article from its publisher.
Shop - Dine - Discover
Meet Local Businesses
Support the businesses that help make our communities thrive. From family-owned shops and restaurants to trusted local services, discover businesses worth visiting throughout the county.
My Local Guide
Explore Your County
Historic Places and Public ResourcesFind local history and useful public information to help plan your next day out.
Historic Places
County Services
Parks and Trails
Libraries and Learning
Plan Your Journey
Explore the History
Photo Credits
View photographers, original sources, and licenses for Rock County on our Picture Attribution page.
Every community has a story.Explore the places that tell it.