August 25, 1804, was a stiflingly hot day when members of the Lewis & Clark Corps of Discovery visited Spirit Mound. They came to the site because they had heard that little people with big heads inhabited the mound. At the mound the expedition didn't find any little people, but did find a "most butifull landscape."
Years later, the Flood Control Act of 1944, authorized the construction of six main dams in the Missouri River Basin. In addition to flood control, the intent of this act was to provide hydroelectric power. With the damming of the river, most of the sites where the Lewis and Clark Expedition camped or visited are now underwater. There are very few places where a person can stand today and know that Lewis and Clark stood in the same exact location. Spirit Mound is one of those few special sites.
In order to provide Spirit Mound visitors with an opportunity similar to what Lewis and Clark experienced, the site is being restored. Prairie grasses and other native plants are being reestablished. The prairie restoration began in 2001 and will take decades of growth before it becomes a good representation of the prairie as seen by the expedition.