Fort Raymond is the start and end of the loop. Manuel Lisa built it at the Bighorn-Yellowstone confluence in November 1807 — the first American trading post in the Rocky Mountains. Lisa was paying Colter to walk west and recruit the Crow to bring furs in; everything that follows starts here. It is also the cleanest place on the route to lead with Indigenous geography: the fort sat on Crow homeland, and the trade Lisa intended was Crow trade.
The Yellowstone–Bighorn confluence is and has been Crow (Apsáalooke) country. Lisa picked this site because the trade he wanted was Crow trade — and the Crow had been trading furs into the region's older networks for generations before any American showed up.
Colter's outbound mission in November 1807 was, in practical terms, a Crow recruiting mission. He carried trade goods west to invite Crow bands to bring furs back to Lisa's new post. Wherever he walked, he was walking into Crow geography that had names, trails, and seasonal logic already written into it.
The modern Crow Reservation sits adjacent to the historic fort site. Crow THPO consultation is the first call before this profile is published with anything more than this Phase-1 framing.
Lisa built Fort Raymond (also called Fort Manuel) in November 1807 with about 50 men, on the south bank of the Yellowstone just above the Bighorn confluence. It was the operating base for the Missouri Fur Company's first season in the Rockies.
The economic logic was simple: get a permanent post west of the Mandan villages, recruit Indigenous trappers and trade partners to bring beaver in, and undercut the British Hudson's Bay and North West companies still working the country from the north. Colter's solo winter walk west and south was a piece of that logic, not a heroic side-quest.
Colter departed Fort Raymond in late October or early November 1807 with roughly thirty pounds of trade goods and no companions. He returned in spring 1808. The walk is what makes him conventionally famous; the trading post that paid for the walk is usually a footnote in the same telling.
The fort's exact site is uncertain. Two candidate locations have been argued; both sit on what is now private ranchland in Big Horn County, MT. No standing remnants survive. NPS has interpretive signage in the general area but does not mark a single confirmed footprint.
We also do not know the route Colter took westward from the fort with any precision. The 1814 Clark map is the closest record, drawn from spoken testimony three years after the walk; secondary sources have argued for at least two divergent first-leg paths.
The fort site is on private land — there is no public-access historic site to visit. The interpretive context lives at the Yellowstone-Missouri Confluence downstream (Confluence Interpretive Center, ND/MT line) and at the Western Heritage Center in Billings, MT. The river corridor itself is the experience: I-90 east of Billings parallels the Yellowstone within sight of the historic reach.
Planned for Phase 3: drone overflight of the confluence area; on-the-ground 360° at the closest public access; oral-history co-production with Crow THPO if scope permits.
Sources & attribution: Crow Tribe THPO (consultation pending) · Burton Harris, John Colter: His Years in the Rockies (1952) · Merrill J. Mattes, Colter's Hell and Jackson's Hole (NPS, 1962) · Discover Lewis & Clark · Wikipedia Fort Raymond