Griswold Conservation Area has an interesting geologic history. The tall mound, formed by the glaciers, rises 80 feet above the surrounding farmland. At 706 feet above sea level, it is the second highest point in Macon County and provides spectacular views. On a clear day you can see four counties.
The mound is a glacial kame, or a cone-shaped hill of gravel that forms as a glacier melts. Kames form at intersections of ice crevices as water, carrying gravel from on top of the glacier, drains through the crevice. This kame was left behind with the melting of the lllinois glacial episode 75,000 years ago.