THE CASS COUNTY LAND BRIEF
Land in the
Upper Mississippi Alluvial Plain setting.
Cass County has 375.8 square miles of land in Illinois. 4 mapped landscape regions meet across Cass County: Upper Mississippi Alluvial Plain, River Hills, Western Dissected Illinoian Till Plain, among others.
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.
Regional context: Interior River Valleys and Hills ↗ · Regional mapping across the county footprint
Where the landscape changes
Cass County intersects 4 mapped regional units. The largest mapped shares are:
- Upper Mississippi Alluvial Plain41.9%
- River Hills34.8%
- Western Dissected Illinoian Till Plain15%
- Illinois/Indiana Prairies8.3%
Central Corn Belt Plains in Cass County
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.
Read the regional source ↗Finding your parcel within Cass County
The atlas lists 16 cities, towns, townships, and Census communities associated with Cass County, including Bluff Springs, Hagener, Sangamon Valley. The list includes overlapping geography types and does not divide the county into exclusive service areas.
Cass County by land and water
The Census records 7.94 square miles of water within Cass County, or 2.1% of its total area. That share is close to Cass County’s 2.1%. This is geographic context; waterfront status and usable land must be checked at the parcel.
For scale, Cass County has 311.3 times the land area of nearby Virginia city (1.21 square miles). These areas describe boundaries, not comparable property prices.
The Census boundary meets Brown County, Mason County, Menard County, Morgan County, Sangamon County, Schuyler County within Illinois. A tract near one of these lines should be matched to the county identifier on its own records.

