Never an official U.S. Military outpost, Fort Bonneville in Wyoming was a fur trading post built by Captain Benjamin Bonneville in 1832.

Taking an extended leave of absence from the Army, Bonneville wanted to explore the Rocky Mountains, explore the fur trade, and report back to the government on his findings, including the character and customs of Native American tribes. Financed by John Jacob Astor of the American Fur Company, Captain Bonneville and Joseph Rutherford Walker headed West in May 1832 with an expedition that included 110 men, about 20 wagons, and an assortment of mules, horses, and cattle. They departed from Fort Osage, Missouri, traveled up to the Platte River, and crossed present-day Wyoming following the tracks of the fur traders. They were the first to take wheeled vehicles across the South Pass and the continental divide of the Rocky Mountains.

They reached the Green River in August. Apprehensive about hostile Blackfeet Indians nearby, he directed his men to build a fortified Winter camp on the right bank of the Green River. The stockaded structure was designed primarily for protection, but Bonneville probably intended it to become a fur trading post.

However, Joseph Walker opposed building the fort and soon left the site to find a group of free trappers nearby. Walker soon returned with several trappers who told Bonneville about the severe winters in the Green River Valley and advised him that the Salmon River area had milder winters and was better trapping country than the Green River Valley. Bonneville was immediately convinced, but when nature intervened with early, heavy snowfalls, he and his men abandoned the post and moved to the Southwest, where they spent the remainder of the year.

The considerable labor expended in constructing Fort Bonneville, followed by its almost immediate abandonment, led many to call it “Fort Nonsense” or “Bonneville’s Folly.” It was described as a 100-foot-square stockade with two blockhouses in the diagonal corners, or as little more than a cluster of small, simple log huts.

In 1835, it hosted “The Green River Rendezvous” and was used by fur traders until 1839.

Though Bonneville’s post had little lasting significance, it was the first of its kind in the region and heralded the fixed trading-post concept in the fur trade.

Today, no signs of the fort remain, except a boulder placed by the Daughters of the American Revolution and a Wyoming Historical Marker. The site is located approximately three miles northwest of Daniel, Wyoming.

The site was placed on the National Register of Historic Places in 1970.

 

©Kathy Alexander/Legends of America, updated October 2026.

Also See:

Explorers, Traders & Trappers

Forts of Wyoming

Forts Across America

Wyoming Main Page

Sources:

The Fur Trapper
Wikipedia
Wyoming State History Preservation Office