Fort Osage, as suggested by Lewis and Clark in 1804, was built to guard traffic along the Missouri River and control the fur trade with Native Americans, particularly the Osage, Kansa, and Iowa tribes. The reconstructed fort became a National Historic Landmark in 1961 and is designated by the National Park Service as a site o­n the Santa Fe and also the Lewis and Clark Trails.

On June 23, 1804, Lewis and Clark documented and suggested the future location of what was to become Fort Osage. Four years later, William Clark with 80 volunteer dragoons from St. Charles and the regular garrison under the command of Captain Eli Clemson, erected a fort a few miles upstream o­n a high bluff overlooking a large meander of the Missouri River, in what is now the village of Sibley in northeast Jackson County, MO.

Soon after arriving, Clark sent Nathan Bone and interpreter Paul Loese to the Osage villages to invite them to take up residence near the new fort. When they did so, Clark drafted a treaty in which the Osage relinquished a large portion of their lands in what is now Missouri and Arkansas. This treaty was not ratified by Congress, but another treaty drafted by Governor Meriwether Lewis was signed at the fort o­n Nov. 10, 1808, and was ratified thereafter.

Closed in June, 1813, during the War of 1812, Fort Osage was reopened in 1815 after the war was over and garrisoned until 1819. George C. Sibley, the fort’s factor, was married in 1815 and brought his new wife, Mary, with him when Fort Osage reopened. He built a house known as Fountain Cottage Farm west of the fort and the couple resided there for the next few years. (Mary Sibley is now recognized as the founder of Lindenwood University in St. Charles).

In 1822 the U.S. abandoned the Factory system, ended government trade at Fort Osage, and replaced it as a military garrison with Fort Leavenworth, KS. In 1825 Fort Osage saw its final service as the starting point for an expedition to survey the Santa Fe Trail. George Sibley, the fort’s former factor, served as o­ne of the expedition’s three commissioners.

Because of its role in the westward expansion of the United States, the Fort Osage site was listed as a National Historic Landmark in 1961 and more recently designated by the National Park Service as a site o­n the Santa Fe and Lewis and Clark Trails. Nearby Hopewell and Osage sites are listed separately o­n the National Register of Historic Places.

— information from the Jackson County Parks and Recreation

For more information about the reconstructed fort, open to the public under the auspices of Jackson County Parks and Recreation, go to