Here is a web site with an article I wrote about glacial beach ridge and swale habitat of the Thumb in the Lakeshore Guardian paper:
"Those living near Lake Huron, especially in Saint Clair County, are probably familiar with the large ridges of sand that parallel the lakeshore, some over a mile inland. Unlike wind-formed sand dunes along Lake Michigan, these ridges are actually old beaches, deposited by ancient waves thousands of years ago. Known as glacial beach ridges and swales, the swales being the lower areas between the ridges, this landscape formed along the Thumb shoreline roughly 4,500 years ago, about the same time the great pyramids of Egypt were constructed."
I'm aware that there are older beaches inland, but from my experience and understanding, these are primarily individual ridges, similar to sand ridges along glacial drainageways, lacking the characteristic ridge and swale pattern that occurs along the shoreline. This landscape is described in greater detail in the "Wooded dune and swale complex" community abstract available on the Michigan Natural Features Inventory web site.
While much of the habitat in the lower Thumb may not be considered as well developed as that in other counties, some of it is. In my opinion, it warrants more attention, and certainly much better treatment than it has received left to the hands of most wetland consultants plying their trade in the booming commercial expansion north of Port Huron in the 90's.
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