THE CARROLL COUNTY LAND BRIEF
Land in the
Rock River Hills setting.
Carroll County has 445.4 square miles of land in Illinois. 3 mapped landscape regions meet across Carroll County: Rock River Hills, Blufflands and Coulees, Upper Mississippi Alluvial Plain.
Glaciated plains historically supported tallgrass prairie mixed with oak and hickory woodland. Dark prairie soils and broad farming landscapes distinguish much of the Central Corn Belt.
Regional context: Central Corn Belt Plains ↗ · Regional mapping across the county footprint
Where the landscape changes
Carroll County intersects 3 mapped regional units. The largest mapped shares are:
- Rock River Hills75.7%
- Blufflands and Coulees14.5%
- Upper Mississippi Alluvial Plain9.8%
Driftless Area in Carroll County
Deeply cut valleys divide a bedrock plateau with windblown soil on many uplands. Glaciers had less influence here than in neighboring regions, leaving a distinctly hilly landscape.
Read the regional source ↗Interior River Valleys and Hills in Carroll County
Broad terraced river valleys contrast with wooded slopes and dissected glacial plains. Bottomland settings and upland oak landscapes occur close together across the Interior River Valleys and Hills.
Read the regional source ↗Finding your parcel within Carroll County
The atlas lists 20 cities, towns, townships, and Census communities associated with Carroll County, including Rock Creek-Lima, Cherry Grove-Shannon, York. The list includes overlapping geography types and does not divide the county into exclusive service areas.
Carroll County by land and water
The Census records 21.6 square miles of water within Carroll County, or 4.6% of its total area. That share is close to Carroll County’s 4.6%. This is geographic context; waterfront status and usable land must be checked at the parcel.
For scale, Carroll County has 222.4 times the land area of nearby Mount Carroll city (2 square miles). These areas describe boundaries, not comparable property prices.
The Census boundary meets Jo Daviess County, Ogle County, Stephenson County, Whiteside County within Illinois. A tract near one of these lines should be matched to the county identifier on its own records.

