Spirit Mound Historic Prairie State Park

Spirit Mound Historic Prairie is a state park in Clay County, South Dakota, United States, featuring a prominent hill on the Great Plains. The Plains Indians of the region considered Spirit Mound the home of dangerous spirits or little people; members of the Lewis and Clark Expedition climbed it on August 25, 1804. The park was established in 2002. It is located about 6.5 miles (10.5 km) north of Vermillion, South Dakota.