Rockwell Mound is one of the site that the Register has denoted as being "address restricted" because of its special sensitivity. Despite this designation by the Register the mound is operated as a park as of 2007.
Rockwell Mound is one of the largest mounds ever built in the Illinois River basin. The earthen mound dates to around AD 200, covers almost 2 acres (8,100 m2), and is about 12 feet (3.7 m) tall. The park that is on the site today is about six miles (10 km) from another Mississippian site on the Register in Illinois, Dickson Mounds.