Beattie Park in downtown Rockford, Illinois, preserves a small surviving remnant of a larger Late Woodland mound complex near the Rock River. The remaining earthworks include three conical mounds, a turtle-shaped effigy mound, a linear mound, and a mound remnant outside the park. Built by several interacting Native American communities during the Effigy Mound Period, about 700 to 1100 C.E., the Rockford mounds likely date from the earlier part of that era. Once far larger, the complex lost some mounds to modern construction. These earthworks remain an important and highly visible survival of northern Illinois’s Indigenous past and the wider effigy-mound tradition.