About Monroe County

Driftless Region > what does this mean?

The Driftless Area is a region in southwestern Wisconsin, southeastern Minnesota, northeastern Iowa, and the extreme northwestern corner of Illinois. The region escaped the flattening effects of glaciation during the last ice age and is consequently characterized by steep, forested ridges, deeply carved river valleys, and karst geology characterized by spring-fed waterfalls and cold-water trout streams.

Ecologically, the Driftless Area’s flora and fauna are more closely related to those of the Great Lakes region and New England than those of the broader Midwest and central Plains regions. Colloquially, the term includes the incised Paleozoic Plateau of southeastern Minnesota and northeastern Iowa. The region includes elevations ranging from 603 to 1,719 feet (184 to 524 m) at Blue Mound State Park, and covers 24,000 square miles (62,200 km2).  The rugged terrain is due to the lack of glacial deposits, or drift, and to the incision of the upper Mississippi River and its tributaries into bedrock.

An alternative definition of the Driftless Area includes the sand Plains region northeast of Wisconsin’s portion of the incised Paleozoic Plateau in the southwestern part of the state. This part of the Driftless Area in the southwestern section of Wisconsin’s Central Plain also lacks evidence of glaciation, and contains many isolated hills, bluffs, mesas, buttes, and pinnacles that are outlying eroded Cambrian bedrock remnants of the plateau to the southwest.