The silt cap results in a diverse groundcover flora as well as tree species not commonly occurring on the more prevalent sandy loam soils in this part of the State. Continental, with heavy snows and extremely cold winters.
Glacial drift covers bedrock, which is only locally exposed.
The predominant bedrock types are Precambrian basaltic to rhyolitic metavolcanic rock with some metasedimentary rock. In Michigan, the western part of the Menominee Iron Range is within the sub-subsection. Drumlin ridges and adjacent swampy depressions that are oriented northeast-southwest. Among the larger lakes are North Twin, Big Sandy, Long, and Smoky in Wisconsin, as well as Smoky, Brule, Golden, Chicagon, Stanley, Ottawa, and James in Michigan. Smaller kettle lakes are also scattered throughout.