The sub-subsection forms a narrow band around the northeastern and northwestern edge of the Highplains subsection. Thick glacial ice in the glacial Great Lakes basins to the north advanced and retreated numerous times, creating a steep and irregular topography of moraines and outwash plains in this subsection. Growing season is 70 to 120 days.
Frost danger is extreme throughout the growing season.
Snowfall ranges from 140 inches in the northwest to 60 inches in the southeast. Heavy snows in the northwest are lake-effect snows off Lake Michigan. No exposures of bedrock. Steep moraine ridges surrounded by outwash channels and plains. Outwash deposits occur both as relatively narrow channels between the steep moraines and as broad plains.