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.

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 Mississippi and Missouri floodplains have up to 150 feet (46 m) of unconsolidated Tertiary and Quaternary alluvium (gravel, sand, silt, and clay) over the bedrock, thinner in the river valleys.

Cretaceous shale and sandstone occur in the northwestern corner, the Nebraska, Minnesota and Iowa boundary section.

Its western boundary is about 100 miles (160 km) west of the Missouri Rivers border along the Kansas/Missouri – Nebraska/Iowa state line.