Effigy Mounds National Monument
Effigy Mounds National Monument preserves more than 200 prehistoric mounds built by pre-Columbian Mound Builder cultures, mostly in the first millennium CE, during the later part of the Woodland period of pre-Columbian North America. Numerous effigy mounds are shaped like animals, including bears and birds.
Source: Wikipedia — Effigy Mounds National Monument (CC BY-SA 4.0)