Illinois State Museum

Variation Across Space

"Ecosystems are a product of both past and present conditions. The variations that we see as we move across Illinois result from differences in local environments. Northeastern Illinois doesn’t look like southern Illinois. The climate and geologic history of each area are different. As a result, many of the plants and animals in each area are also different. In the current Interglacial area, we have developed habitat reconstructions for seven Illinois ecosystems."

The Natural Divisions of Illinois
Scientists recognize 14 natural divisions in Illinois. The divisions are based on differences in topography, soil, bedrock, glacial history, plants, and animals.

Wisconsin Driftless Division
Rock River Hill Country Division
Northeastern Morainal Division
Grand Prairie Division
Upper Mississippi River and Illinois River Bottomlands Division
Illinois River and Mississippi River Sand Areas Division
Western Forest-Prairie Division
Middle Mississippi Border Division
Southern Till Plain Division
Wabash Border Division
Ozark Division
Lower Mississippi River Bottomlands Division
Shawnee Hills Division
Coastal Plain Division