Established as a American Fur Company trading post in 1844 replacing Fort McKenzie. Fort McKenzie was deliberately abandoned and later burned in 1844 by traders Francois Chardon and Alexander Harvey, they then built Fort Chardon on the south bank of the Missouri River near the mouth of the Judith River. Chardon's inhumane treatment of the Blackfeet at Fort McKenzie followed him to the new post and nearly all the Blackfeet trade was lost.
Alexander Culbertson was sent by the Company to replace Chardon in an attempt to recover the lost Blackfoot trade. Culbertson had a record of fair-dealing trade with the Indians but Fort Chardon was no longer viable. Culbertson abandoned it in 1845 and built a new post, Fort Lewis, three miles upriver from Fort Benton.