The Region Between the Appalachians and the Mississippi: Interior Lowlands

Name & Extent

The vast territory between the Appalachian Mountains (east) and the Mississippi River (west) is the Interior Lowlands (also called the Central Lowlands or Midwestern U.S.).

Subregions

• Great Plains (western fringe, west of 98th meridian).
• Central Lowlands (glaciated till plains: Ohio, Indiana, Illinois, Iowa, Missouri).
• Ozark Plateau (southern Missouri, northern Arkansas).
• Interior Highlands (Ouachita Mountains, Arkansas Valley).

Characteristics

• Flat to gently rolling terrain.
• Deep, fertile soils (Mollisols, Alfisols) — Corn Belt, Soybean Belt.
• Drained by Mississippi tributaries: Ohio, Missouri, Arkansas, Red, Tennessee Rivers.
• Humid continental to subtropical climate.
• Prairie, savanna, oak-hickory forest, wetland mosaics.

Economic Engine

America's agricultural heartland, manufacturing corridor, and transportation nexus (rail, barge, highway, pipeline).