The Driftless Region
An ancient land spared from glaciation.
The Driftless Region is a distinctive geologic and cultural region in the Midwest that encompasses southeastern Minnesota, southwestern Wisconsin, northeastern Iowa, and the extreme northwestern corner of Illinois all along the mighty Mississippi River. The area was not covered by ice during the last ice age, which resulted in the absence of the usual glacial deposits known as drift. The Driftless Region is characterized by its dramatic hills, valleys, and karst topography with cold-water trout streams, caves, and rock outcroppings. The mosaic of different habitats in the Driftless promotes greater biodiversity. Many animals and plants are unique to the Midwest, often only found elsewhere on the continent or even nowhere else at all.
Most of the land in the Driftless has been dominated by human development - largely due to agriculture - leaving very little of the natural landscape. There are numerous protected areas scattered across the region, but these preserves rarely exceed 2,000 acres.
Left: The Driftless Area (Source: USDA). Right: Maximum extent of the ice sheet (blue) during some relevant glacial episodes: (a) early Pre-Illinois (approx 1,000,000 years ago); (b) late Pre-Illinois (approx 600,000 years ago); (c) Illinois (approx 250,000 years ago); (d) late Wisconsin (approx 22,000 years ago). The Driftless Area is shown in grey; arrows indicate direction of ice movement. (Source: Illinois State Geological Survey), Image assembled from http://www.rafamedina.com/research/bryda/
Map of the Driftless region (red line) showcasing the various types of protected lands by state and local entities (green), U.S. Fish and Wildlife Service (brown - much of this the Upper Mississippi River National Wildlife Refuge), U.S. National Park Service (pink - Effigy Mounds National Monument), and various conservation programs (orange).