By 1828 he had established his first trading post, Fort Uncompahgre, in the intermountain corridor of the western slopes of the Rocky Mountains on the Gunnison River near present-day Delta, Colorado.

That same year, Robidoux took out Mexican citizenship and married Carmel Benevedes, the daughter of the governor of New Mexico.

Once his operations were well established on the Gunnison River, Robidoux purchased both the site and business from Reed and expanded their operation by building the larger Fort Robidoux and bringing in trappers to trap the beaver-rich streams of the Green and Uintah rivers.

Robidoux successfully competed in the Uinta Basin region's fur trade against competition from Fort Davy Crockett, the American Fur Company, the Hudson's Bay Company, and traders out of Bent's Fort.

[1] During his years in business such notables as Kit Carson, Miles Goodyear, Marcus Whitman, Joe Meeks, Captain John C. Fremont, August Archambeaux, Rufus Sage, and the Reverend Joseph Williams all visited Fort Uintah.