Spirit Mound Historic Prairie is a state park of South Dakota, USA, 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.
Spirit Mound was in private hands for many decades, leading to extensive degradation of the site's original status. White settlers first came to the area in 1868, and used it for grazing livestock and for farming. Five separate landowners owned parts of the site in the early 1980s. More than 20 buildings, a feed lot, soybean fields, corn fields, several roads, 1,500 non-native trees, and 5 miles (8.0 km) of fence dotted the site.