thumb|400px|Continental U.S. physiographic regions. Region 12e identifies the Dissected Till Plains.
The Dissected Till Plains are physiographic sections of the Central Lowlands province, which in turn is part of the Interior Plains physiographic division of the United States, located in southern and western Iowa, northeastern Kansas, the southwestern corner of Minnesota, northern Missouri, eastern Nebraska, and southeastern South Dakota.
The Dissected Till Plains were formed during the Pre-Illinoian Stage. Glacial scouring and deposition by the Laurentide Ice Sheet and the later accumulation of loess during the Wisconsin Stage left behind the rolling hills and rich, fertile soils found today in the region.
The region is also the western edge of the Corn Belt.
Geology
As a part of the Central Lowland geomorphic province. It is a glacier till plain from flat to rolling plain that slopes towards either the Missouri or Mississippi rivers. It is moderately dissected. Local relief is . The region is pocketed by small human landform, i.e., strip-mines among a hummocky or ridge-swale topography. Streams drain and erode the area, moving soils and depositing them downstream. Elevation ranges from .
thumb|Loess hills in western Iowa
Loess (unconsolidated aeolian silt), as much as thick thins toward the east, covers most uplands. Pleistocene (pre-Illinoisan) till lies beneath the loess, covering the bedrock up to deep. Along the edges, it thins to less than . The Mississippi and Missouri floodplains have up to of unconsolidated Tertiary and Quaternary alluvium (gravel, sand, silt, and clay) over the bedrock, thinner in the river valleys.
thumb|Southern Iowa Drift Plain
- Missouri – The northern tier from the Missouri Valley between St. Louis and Kansas City north to the Iowa border.