Where IS the Driftless?!?!

The "driftless" is a rare unglaciated area primarily located in west central and southwestern Wisconsin along the east side of the Mississippi River and just kissing northwestern Illinois. While both southeastern Minnesota and northeastern Iowa seem to share the same characteristics of the Driftless, they are actually not part of the unglaciated area and are outside the actual Driftless area.

From Wisconsin Geological and Natural History Survey. The Driftless Area. Educational Series 057.
Carson, E. C., Curry, B.B., Kerr, P.J. Lusardi, B.A.  University of WI Madison, 2023.

That can sometimes be hard for people to wrap their heads around. The area is a special gem of steep bluffs towering over the Mississippi River and a winding network of long valleys, bluffs and steep hills continuing outward from the river that create a magnificent landscape. It is a challenging environment in which to build, farm and recreate in. We all want to claim it as our own and have a fierce love of this landscape.

Alot of areas in southeastern Minnesota and northeastern Iowa across the Mississippi River sure look like the Driftless area to the west in Wisconsin and Illinois. There is a tendency - which even I have shared - to claim these nearby areas as part of the Driftless. But they actually experienced glaciation during the Pre-Illinoian Glaciation era (500K-2,600K ago). These areas don't display the lack of glacial sediment or "drift," as it was called in the mid-19th century, that the Driftless does.

A just-published pamphlet "that describes and outlines the boundary of the unglaciated Driftless area based on modern geologic evidence" breaks down the differences in easily understood language. Titled The Driftless Area: The Extent of unglaciated and simitar terrains in Wisconsin, Illinois, Iowa and Minnesota, and authored by members of each states' geological survey team, this brief pamphlet (2 pages of text and 2 pages of citations!) is a perfect short explanation of what is the Driftless area - and what isn't.

Because the Driftless area in Wisconsin and Illinois never experienced glaciers, it is truly "the Driftless."  The rugged landscape of bluffs, steep hillsides and coulees displays no evidence of glaciation. Rather the landscape was formed by rivers cutting down through the sediment and forming deep valleys. 

In surrounding areas in portions of southeastern Minnesota and northeastern Iowa, there is clear evidence that the Pre-Illionoian glaciation left glacial landforms and sediment.  However, because they are Mississippi River-adjacent, they were also steeply cut into by rivers and so they are topographically similar to the Driftless.

The four-state geological survey team suggest that it would be more accurate to say these areas display "Driftless-style topography." They are not truly Driftless.

From Wisconsin Geological and Natural History Survey. The Driftless Area. Educational Series 057.
Carson, E. C., Curry, B.B., Kerr, P.J. Lusardi, B.A.  University of WI Madison, 2023.

I'm perfectly good with being Driftless-adjacent in Minnesota. I'll be keeping the blog title as is but I'll be going back and adding a "Driftless area" tag to all blog posts of hikes that are truly in the Driftless. I also edited the blog's header slightly to reflect more accurately the distinction.

The more we know, the more we grow!  I love how scientific knowledge keeps evolving as research and knowledge is continually added to. It helps us to better know the world around us even as it refines - and sometimes - shakes up our understanding.