Spirit Mound Historic Prairie, SD
Upon nearing present-day Vermillion, SD on August 25, 1804, the Corps had heard tales of "a hill of little deavils," that was said to be inhabited by spirits, which kept area Indian Tribes from visiting the landform. thirteen members of the expedition, and Lewis's dog, Seaman, trekked to the hill. Clark wrote, "the Mound which the Indians Call Mountain of the little people or spirits. . .from the top of this Mound we beheld a most butifull landscape; Numerous herds of buffalow were Seen feading in various directions."

Spirit Mound Historic Prairie is in the process of being restored to naitive prairie grasses. Spirit Mound continues to be a sacred site for several area tribes.