The remains of the most sophisticated prehistoric native civilization north of Mexico are preserved at Cahokia Mounds State Historic Site. Within the 2,200-acre tract, located a few miles west of Collinsville, Illinois, lie the archaeological remnants of the central section of the ancient settlement that is today known as Cahokia. Cahokia Mounds is a not-for-profit organization managed by the Illinois Historic Preservation Agency as a State Historic Site.
