Zimmerman Kame

Zimmerman Kame is a glacial kame and archaeological site in McDonald Township near the community of Roundhead. A circular hill approximately 20 feet in height, it was a commercial gravel pit for a time before being abandoned in the 1970s after artifacts of the ancient Glacial Kame Culture of Native Americans were found at the site. Today, the kame is tree-covered and surrounded by farm fields; there are no obvious signs of its significance.
-from Wikipedia