Geology
During the Illinoisan Stage between 352,000 to 132,000 years ago, the Laurentide ice sheet covered up to 85 percent of Illinois. The southern area of this ice sheet was located in what is now the Shawnee National Forest. Because of this, there are tons of interesting and spectacular bluffs and overlooks located throughout the entire park. The geologic processes that formed the landscape are partially responsible for the presence of important mineral resources, including some of national significance.
