Fort Pierre Chouteau, established in 1832 by Pierre Chouteau, Jr. near the Missouri and Bad rivers in present-day central South Dakota, became one of the upper Missouri’s most important trading posts and the largest in the northern Great Plains. Built to replace flood-prone Fort Tecumseh, it served the American Fur Company as a strategic commercial center and route connection toward Fort Laramie. Lakota Sioux and other Plains peoples traded buffalo furs there for American and European goods, and at its height in the 1850s about 100,000 robes passed through the post. Its decline followed bison overhunting and shifting frontier logistics, and archaeological work later confirmed its location and remains.