About this route: Colter left no journal. The geometry here is the probable route reconstructed from William Clark's 1814 map and the work of Vinton (1926), Harris (1952), and Mattes (1962). Every segment carries a confidence rating. Treat this as scholarship — not a verified track.
Where this fits

The first dedicated public map of Colter's route.

A focused ArcGIS Online search in May 2026 turned up zero authoritative public web maps of the 1807-08 traverse. NPS Lewis & Clark NHT layers stop in 1806. Generic Yellowstone storymaps treat Colter as a footnote. Static page treatments at bigskywords.com and discovergrandteton.org get you a JPG and a page of text. That's the field.

What lives at coltertrace.org

A dedicated standalone site for a chapter the existing NHT / NPS / state-tourism web doesn't currently carry. Two surfaces: a narrative landing chapter, and a full-bleed interactive map with the layers Jacob Dixon (Oregon State GIS, interning with the L&C NHT) built in spring 2026.

The auto route is the tourism call-to-action. The probable Colter route — with every segment confidence-rated — is the honest scholarship layer underneath.

Why standalone, not under another site

Colter left the Corps in August 1806. The 1807-08 traverse is post-expedition and is its own story; it shouldn't live as a subpage of Lewis & Clark or of the Missouri. Yellowstone Forever, the Grand Teton NP Foundation, the Buffalo Bill Center of the West, and the Museum of the Mountain Man are all natural distribution partners that don't sit under any single parent brand.

Same architecture pattern as iceagefloodstrail.org — scholarly orgs keep their own identity, Terrain360 operates the immersive public layer.

Gold line on the hero map above is the Auto Route — the modern highway tour assembled from Jacob Dixon's JohnColter_AutoRoute layer (US-89 / US-191 / US-287 / US-26 / US-14 / US-16 / US-20 / US-212 / WY-296 / WY-120). The blue dashed line is the probable Colter route from Clark's 1814 map, with every segment confidence-rated. YELL + GRTE boundaries are loaded live from NPS Open Data. Historical markers from HMdb.org. The full standalone map ships at coltertrace.org/map

The full story

Three chapters. None of them a footnote.

The 1807 traverse is usually told as a "first non-Native description of Yellowstone" story. That's one chapter. The country Colter walked carried two longer ones — a fur-trade economy that paid for everything he did, and Indigenous homelands he was walking through, not into.

Colter was the first to report back to St. Louis what he had seen. He was not the first to be there.
First & ongoing

Indigenous homeland

Crow (Apsáalooke) east of the Absarokas. Eastern Shoshone and Bannock in the Wind River, Jackson Hole, and Pierre's Hole. Blackfeet (Niitsitapi) to the north. None of the country Colter walked was empty.

The 1807-08 traverse was a winter trade mission into known Indigenous geography, conducted with Crow guides for at least part of the loop. The 1808 escape from Blackfeet warriors near Three Forks — Colter's Run — is the most-told single anecdote about him. It needs careful telling: the Blackfeet were defending homeland during a generational conflict that began with the Two Medicine killing on Lewis & Clark's 1806 return.

Crow / Eastern Shoshone / Blackfeet Tribal Historic Preservation Office consultation before publish — not after.

The fur-trade chapter

Manuel Lisa's economy

Lisa's Fort Raymond, built November 1807 at the Bighorn-Yellowstone confluence, was the first American trading post in the Rocky Mountains. Colter was sent west because that's what Lisa was paying him to do. His 1808 trip (the famous Run) was a trade expedition with John Potts — not exploration.

Colter dies in 1812 or 1813 in Missouri, just a few years after walking back from the Tetons. The fur-trade economy that paid for the whole story is the connective tissue of the route. The Museum of the Mountain Man in Pinedale is the primary interpretive institution for the chapter.

Lisa's Fort. Pinedale. Three Forks. Colter's death in St. Louis. The fur-trade economic geography that frames every choice he made.

Discovery — carefully

"Colter's Hell" and the rest

Colter is credited as the first non-Native to describe what is now Yellowstone and Grand Teton. The credit is real. The framing matters.

"Colter's Hell" is the cleanest example. Per USGS — the sulfur springs and fumaroles he described to Clark were on the Shoshone River west of present-day Cody. Not the Yellowstone geyser basins. Nineteenth-century writers conflated the two; the "Colter discovered the geysers" story is a later invention. The map calls this out where it sits.

The Colter Stone — found 1931 outside Tetonia, ID; inscribed "John Colter / 1808"; on loan to the Teton Valley Historical Museum — is a public-curiosity hero pin, not evidence. The map treats it that way.

What this means for the build

Practically, this changes a few things about how coltertrace.org gets built — versus a simpler "drive the route" tourism product:

  • Confidence is rendered on the map. Jacob's Confidence field (High / Medium / Low) drives line opacity. Low-confidence segments visibly read as speculative.
  • Crow / Shoshone / Blackfeet consultation precedes publish. Lisa's Fort, Colter's Run, and Pierre's Hole each carry a tribal-homeland chapter; copy is co-authored, not written for them.
  • "Colter's Hell" gets a hero site that names the conflation. The USGS-confirmed geography is the lead, not the romanticized version.
  • Highway numbers are in the typography. Jim Mallory's specific ask. US-89/191/287, US-14/16/20, WY-296, US-212, Teton Pass — visible on the auto-route layer at every zoom.
Two surfaces

A landing chapter and a standalone map.

coltertrace.org ships as two distinct pages. The landing is the narrative front door. The map is the working tool — embeddable into any tour-operator, foundation, or museum site that wants it.

DELIVERABLE 01

Landing chapter

Hero, dual-story narrative, embedded preview map, hero Site profiles, partner attribution, phase plan. Lives at coltertrace.org. Funnels traffic to partner orgs and to the standalone map view.

Built on: static HTML · CDN-loaded Leaflet · custom Fraunces + Inter design system · WCAG-compliant dark theme
DELIVERABLE 02

Standalone interactive map

Full-bleed map at coltertrace.org/map. Sidebar Sites index (hero waypoints + 26 HMdb markers in region), filters by site type, deep-linkable URLs (/map#colters-hell), embeddable iframe (?embed=1), mobile bottom-sheet.

Built on: Leaflet · NPS Open Data feature service · Esri imagery + transportation reference tiles · Jacob Dixon's three Esri layer packages (parsed to GeoJSON)
By the numbers

One man. One winter. A whole regional geography.

96auto-route segments mapped
64probable-route segments
57HMdb Colter markers nationwide
26markers in the YELL / GRTE region
1807Fort Raymond opens · Colter departs
1814Clark publishes the route map
1931Colter Stone found outside Tetonia
2026America250 · first public Colter web map
Hero sites

Anchor waypoints from the Yellowstone to the Three Forks.

Twelve anchor waypoints along the loop, each backed by a profile page. Six of them are confidence-flagged because the underlying scholarship is. Three of them carry a tribal-homeland chapter as the lead. One — the Colter Stone — is a public curiosity, not evidence.

Tribal homeland

Manuel Lisa's Fort Raymond

Custer, MT · Bighorn–Yellowstone confluence

First American trading post in the Rockies, built November 1807 on Crow (Apsáalooke) homeland. Launch point of the traverse. Site is private ranchland today.

Thermal

Colter's Hell

Shoshone River · Cody, WY · US-14/16/20

Sulfur springs and fumaroles in the Shoshone canyon — USGS-confirmed as the Cody hydrothermal field, geologically unrelated to Yellowstone. The "Colter discovered the geysers" story is a later conflation.

YELL gate

East Yellowstone Entrance

Buffalo Bill Cody Scenic Byway · US-14/16/20

Where the modern auto route enters Yellowstone. The Cody-to-Yellowstone byway is the scenic-byway proxy for Colter's Shoshone-River leg west of his Hell.

Low confidence

Togwotee Pass

US-26/287 · 9,658 ft

Auto-route proxy for whichever pass Colter actually crossed. Togwotee (today's highway) or Union Pass (no road) — Burton Harris (1952) favored Union; Mattes preferred Togwotee. The single most-debated detail of the entire route.

GRTE corridor

Jackson Hole

Grand Teton NP · US-89/191/26

The valley Colter reportedly described to Clark as "a large hole" — fur-trade vocabulary for an enclosed mountain valley. Likely the southernmost reach of his loop.

Mountain pass

Teton Pass

WY-22 / ID-33 · 8,431 ft

Crossing from Jackson Hole into Pierre's Hole (Teton Valley, Idaho). Trail Creek road is the modern paved proxy.

Curiosity

The Colter Stone

Tetonia, ID · Teton Valley Historical Museum

Rhyolite head-stone inscribed John Colter / 1808, found 1931. On loan from GTNP. Never authenticated. Treat as curiosity, not evidence.

Low confidence

Yellowstone Lake

Yellowstone NP · West Thumb

Whether Colter reached the lake at all is disputed. The Clark 1814 map shows him at "Eustis Lake" — but the geography Clark drew from Colter's testimony is famously distorted.

Grand Loop

Tower / Lamar reach

Yellowstone NP · Grand Loop Road NE

Probable Yellowstone River crossing on the return arc. The modern Grand Loop is the practical auto-route closure before exiting via Beartooth or Chief Joseph.

Scenic byway

Chief Joseph Scenic Byway

WY-296 · over Dead Indian Pass

The loop's most photogenic byway. Named for the 1877 Nez Perce flight — a chapter unrelated to Colter, but the road is the route home.

Scenic byway

Beartooth Pass

US-212 · 10,947 ft

Alternate northern return. Not on Colter's traced path, but a defensible auto-route addition for tourism intent — one of the most-cited scenic highways in the U.S.

Tribal homeland

Three Forks · Colter's Run

Headwaters of the Missouri · 1808

The famous 1808 escape from Blackfeet warriors. Needs careful telling: the Blackfeet were defending homeland during a conflict that began with the Two Medicine killing in 1806. Co-authored with Blackfeet THPO.

Phased delivery

Phase 1 is online before Memorial Day.

Jim Mallory's ask was explicit: get this in front of the Summer 2026 tourist before they hit the park gates. Phase 1 publishes the Yellowstone-Teton loop. Phase 2 extends to the full national HMdb marker corpus. Phase 3 layers 360° capture and oral-history co-production.

Phase 1 · ship June 1, 2026

Public-facing site + map

Yellowstone-Teton auto-route loop with confidence-rated probable route, HMdb markers in region, hero waypoints.

  • coltertrace.org landing chapter + /map standalone
  • Jacob Dixon's three Esri layers → GeoJSON, published
  • Live NPS YELL + GRTE boundaries
  • 11 hero waypoints with profile copy
  • 26 in-region HMdb.org markers
  • L&C Trust, NPS LCNHT, OSU credit visible
  • Embed mode for tour operators (Conrad Tausend's company first)
Phase 2

Full national context

Expand to the 30+ markers outside the YT region — Bozeman, Missouri, Virginia, Kansas, Idaho — and the fur-trade economic geography.

  • 57-marker national HMdb corpus
  • Tribal homeland co-authored hero sites (Crow / Shoshone / Blackfeet THPO)
  • Museum of the Mountain Man partnership content
  • Buffalo Bill Center of the West co-authored Colter's Hell profile
  • Curated 7-day / 14-day itineraries
Phase 3

360° capture + oral history

The Terrain360 layer: ground-truth capture at every hero waypoint, plus partner-co-produced audio.

  • 360° capture at Colter's Hell, Lisa's Fort, Teton Pass, Three Forks
  • Drone footage of Jackson Hole, Yellowstone Lake, Beartooth
  • Photogrammetry of the Colter Stone (with GRTE / Teton Valley permission)
  • Co-produced audio with Crow / Shoshone / Blackfeet voices
  • Open-format export — KMZ, GeoJSON, USDZ, glTF
Partners & attribution

Built with the river, the road, and the historians.

Lewis and Clark Trust NPS Lewis and Clark NHT Yellowstone Forever Grand Teton National Park Foundation Buffalo Bill Center of the West Museum of the Mountain Man Lewis & Clark Trail Heritage Foundation Discover Lewis & Clark Crow Tribe THPO Eastern Shoshone Cultural Center Northern Arapaho Experience Blackfeet Nation THPO Wyoming State Historical Society Montana Historical Society Idaho State Historical Society Teton Valley Historical Museum Greater Yellowstone Coalition National Parks Conservation Association HMdb.org · Historical Marker Database USGS · NHD + YVO Oregon State University · J. Dixon Terrain360

For NPS & partners

Questions, content corrections, partnership ideas, capture scope — Ryan Abrahamsen, Terrain360 founder.

ryan@terrain360.com · 804.677.1456 · calendly.com/ryan-terrain360/30min

References

Live Terrain360 builds the team can walk through today.

paddlethemissouri.com · paddletheohio.com · iceagefloodstrail.org · terrain360.com/kentuckyriver

Concept · Pre-launch