Did Rib Mountain cause the “Driftless Area”?
The Driftless Area is a region in southwestern Wisconsin was not glaciated at any time in the past 2 million years (so far as we can figure). However, it was not Rib Mountain that deflected the ice or anything like that. Most likely, it was simply the Great Lakes basins that did that (the Superior and Michigan basins). These basins likely shaped the ice flow and caused it to split and never get across the southwest. Rib Mountain is just not big enough to have had that impact on the ice flow.
