Rim Rock National Recreation Trail and nearby picnic area was initially developed in 1962 and opened to the public in 1963. It is the first Cooperative Forest Trail established on a National Forest in partnership with a women’s club. The Illinois Federated Women’s Club initially was involved in the reforestation of the Shawnee National Forest since its development in the 1930s, and on May 15, 1963, they planted the 3,000,000th pine tree near Pounds Hollow and Rim Rock.
Near the beginning of Rim Rock Trail, the stone path crosses and overlooks the remains of a stone wall that was built over 1,500 years ago. This is the remains of the Pounds site, a prehistoric stone fort that extends 400 feet east to west across a narrow neck on the southernmost edge of the 40 acre bluff top. It is called the Pounds site because early settlers thought it was the remains of an enclosure for trapping animals or a “pound." This is one of 11 stone forts scattered across the Shawnee Hills. Although archaeologists are still uncertain as to why the prehistoric Native American inhabitants built these stone enclosures, excavations conducted by Forest Service archaeologists and volunteers at the Pounds Site found some clues that at least help unravel the mystery. The investigations revealed prehistoric cultural deposits within the stone wall dating to the Late Woodland period, 400-900 A.D. The wall is not a simple rock pile as was traditionally thought, but instead it was built on a prepared foundation of plate-like sandstone slabs and intensely burned soil.