THE MADISON COUNTY LAND BRIEF
Land in the
Southern Illinoian Till Plain setting.
Madison County has 715.5 square miles of land in Illinois. 4 mapped landscape regions meet across Madison County: Southern Illinoian Till Plain, River Hills, Middle Mississippi Alluvial 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
Madison County intersects 4 mapped regional units. The largest mapped shares are:
- Southern Illinoian Till Plain60.7%
- River Hills22.5%
- Middle Mississippi Alluvial Plain16.4%
- Western Dissected Illinoian Till Plain0.4%
Finding your parcel within Madison County
The atlas lists 56 cities, towns, townships, and Census communities associated with Madison County, including Fort Russell, Hamel, Helvetia. The list includes overlapping geography types and does not divide the county into exclusive service areas.
Madison County by land and water
The Census records 24.4 square miles of water within Madison County, or 3.3% of its total area. That share is close to Madison County’s 3.3%. This is geographic context; waterfront status and usable land must be checked at the parcel.
For scale, Madison County has 20.1 times the land area of nearby Pin Oak township (35.7 square miles). These areas describe boundaries, not comparable property prices.
The Census boundary meets Bond County, Clinton County, Jersey County, Macoupin County, Montgomery County, St. Clair County within Illinois. A tract near one of these lines should be matched to the county identifier on its own records.

