The Golden Eagle-Toppmeyer Site in Illinois, near the meeting of the Illinois and Mississippi Rivers, preserves a rare pre-Columbian complex linked to the Havana Hopewell culture. It includes the Golden Eagle earthwork, a Middle Woodland geometric earthwork dating from about 150 BC to 450 AD and the only known example of its kind in the central Mississippi River valley, with a rounded form and two mounds. Overlapping its western edge is the later Toppmeyer habitation site from around 750 AD. Together, these features suggest a regional transaction center where Illinois River valley Hopewell communities exchanged goods and cultural practices.