Shavehead Lake a Glacial Remnant

It began with the discovery in 1929 of large bones in a marl pit in the Chapel Hill Church area north of Union Michigan. These bones (including a 3 foot eleven inch femur) eventually proved to be from a mastodon that measured 10 feet 6 inches at the shoulder and a length of over 13 feet. They were found buried under almost 9 feet of undisturbed marl which is almost pure calcium carbonate, formed from the shells of fresh-water invertebrates and by direct precipitation from the water. The undisturbed condition of the marl beds showed the cadaver had been deposited before the marl was formed. Thus the skeletal remains dated to the beginning of the formation of a large body of water left as a large glacier receded north. This area apparently was termed “Lake Mogodore” by a then area resident named John Eby. The name “Mogodore” had earlier been applied to the narrow valley with a stream that winds southward from Shavehead Lake through and including several lakes to the south. The borders of Lake Mogodore are identified by a welldefined offshore terrace, often consisting of Marl, and in some places by low, wave-cut cliffs. The terrace stands between 35 and 40 feet above the present level of Shavehead Lake and at about the same height above Carter Lake. At Birch Lake, however, the terrace is only about 6 feet above lake level. At its greatest extent Lake Mogodore had a total length of about 6&1/2 miles and a maximum width of about 1 mile. It was irregular in shape and contained several islands. The present drainage starts with Birch Lake (to our north) which is the highest in the Mogodore Basin. It discharges southward into the western arm of Shavehead Lake. The outlet from Shavehead takes a south-easterly course and is joined by the drainage of Carter Lake at the head of the Mogodore Valley. The stream then continues south and east into Long Lake and eventually into the St. Joseph River. According to a Michigan State biologist, today this valley is resident to certain flora and fauna found nowhere else in the world. The diagram below gives you an idea of the area covered by the glacial lake which was discovered in the 1920’s because a mastodon skeleton provided evidence that it had been covered by freshwater shells over thousands of years ago. You can view the wonders of this small valley by canoe or kayak through the marsh lands at the southwestern end of Shavehead Lake or by taking the beautiful and relaxing drive on Carter lake road and Birch Lake road south to US 12.

(Article excerpted from study by Case, Scott, Badenoch and White)