The Dissected Till Plains, an area of rolling hills and fertile soil that covers much of Iowa and Nebraska, extends into the southeastern corner of South Dakota.
32.
The present day river bed has eroded into the till plain surface and is now deeply incised, as are the tributary streams and agricultural drains flowing into it.
33.
The Shell River flows in the Northern Lakes and Forests ecoregion, which is characterized by conifer and hardwood forests on flat and rolling till plains and outwash plains.
34.
The Kettle River flows in the Northern Lakes and Forests ecoregion, which is characterized by conifer and hardwood forests on flat and rolling till plains and outwash plains.
35.
The Dissected Till Plains were formed by pre-Wisconsin glaciations during the Wisconsin Stage left behind the rolling hills and rich, fertile soils found today in the region.
36.
The Fish Hook River flows in the Northern Lakes and Forests ecoregion, which is characterized by conifer and hardwood forests on flat and rolling till plains and outwash plains.
37.
The Dissected Till Plains, an area of rolling hills and fertile soil that covers much of Iowa and Nebraska, also extends into the southeastern corner of South Dakota.
38.
The Le Sueur River flows in most of its course on till plains and on the plain of a former glacial lake, through deeply incised ravines in its lower course.
39.
Ancient mountain trails through eastern Kentucky and West Virginia allowed Native American passage between the northern Till Plains of Illinois, Indiana, and Ohio, and the Piedmont Plateau and Atlantic Ocean coastal plains.
40.
At the surface, the entire region is " Moraine terrain ", with the glacial landforms of moraines, drumlins, eskers, kames, outwash plains and till plains, all relics from recent glaciation.
