There are three parts of the state that have not been covered by glaciers . One is in far Southern Illinois, where the Shawnee Hills National Forest is. Another is in the southwestern part of the state, made up mostly of Calhoun County. The other is in the northwestern corner of Illinois, where Jo Daviess County is. These areas have many hills and valleys, because erosion has worked on the areas for hundreds of thousands of years. The rest of Illinois would probably look this way if it had not been for the glaciers.
