The Osage in exchange for access to the trading post above the Missouri River in 1808 in the Treaty of Fort Clark ceded all of their lands east of the fort in Louisiana Territory effectively leaving them with a small band of territory on the extreme western border of Missouri. The fort ceased operations in the 1820s as the Osage in subsequent treaties ceded the rest of their land in Missouri. A replica of the fort was rebuilt on the site in the 1950s.