Course map, elevation profile & surface
Fly the course
Follow the route over 3D terrain, mile by mile.
Race-day light
For a 23:15 finish (an estimate) · starting 7:00 AM Sep 19 · headlamp mi 62–the finish. Dark means the sun below civil twilight.
Climbs
11 climbs · 13,189 ft totalbiggest firstElevation gain, measured two ways
| Source | Gain | vs lidar |
|---|---|---|
| Course file (GPX) | 14,188ft | -14% |
| USGS lidar, 1 m | 16,471ft | reference |
They differ because a GPS file picks up noise on every wiggle and often takes its heights from a coarse terrain model, while lidar maps the ground itself to about a metre. We sampled this route every 98 ft against USGS 3DEP and counted each rise of 10 ft or more, on Oct 24, 2026. The planner still uses the course file.
Aid stations as published on the course file
| Aid station | Mile | km |
|---|---|---|
| A Chinook Campground | 16.5 | 26.6 |
| A Willow Basket 1 | 19.5 | 31.4 |
| A Diamond Ridge water | 27.4 | 44.1 |
| A Upper Payette Lake 1 | 32.9 | 53.0 |
| A Lake Fork Aid Station | 60.6 | 97.6 |
| A South Crestline Aid | 68.5 | 110.2 |
| A Box Creek Aid | 76.1 | 122.4 |
| A North Crestline Aid | 82.0 | 131.9 |
| A UP2 | 90.6 | 145.7 |
| A The Cloochman Clock | 96.2 | 154.9 |
| A Bear Pete Water & Snackies | 100.6 | 161.8 |
Badge colours match the markers on the map above — always confirm locations and cutoffs with the race organizer.
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Conditions typical race-day weather for Sep 19 at the start
Typical = the median of 2016–2025 for Sep 19 ±3 days at the start line; a wet day has 1 mm of rain or more. Historical weather from Open-Meteo.
Race almanac 1 year of this race
Past editions
On race day it reached 59°F at the start, with a low of 41°.
| Year | Start °F | High point °F | Rain | Wind |
|---|---|---|---|---|
| 2026 Sep 19 | 59°/41° | 51°/37° | 0.15in | 4mph |
race-day weather from the Open-Meteo historical archive (ERA5) at the start line and the course high point (8,045 ft).
Reviews what runners who have been there say
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About this course
IMTUF 100 - Idaho Mountain Trail Ultra Festival 100 Miler — 2026 covers 105.7 mi (170.1 km) with 14,188 ft of elevation gain through Idaho, United States. That is about 134 ft per mile of climbing, and 14,193 ft of descent. The course tops out at 8,045 ft and bottoms out at 5,449 ft. The surface is 57% trail, 36% gravel and 1% paved. There are 11 aid stations on course; the longest stretch between aid is 27.7 mi. The profile has 11 sustained climbs; the biggest is the climb to Bear Pete Water & Snackies, +2,493 ft over 11.9 mi at 4.0% on average (steepest stretch 21%). Race day is September 19, 2026, starting at 7:00 AM; the sun rises at 7:28 AM and sets at 7:49 PM. Typical race-day weather at the start: a high of 59°F and a low of 38°F, with a 39% chance of a wet day. The interactive map above shows the full route with its elevation profile and aid stations, built from the course's GPS file.
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Course history
- Sep 3, 2026Added to the catalog
Races like this one close in distance, climbing, terrain, altitude, weather and season
- Bryce Canyon Ultras — 2026Sep · 99 mi · 135 ft/mi · UTSimilar climbing · Similar terrain · Same distance
- Mogollon Monster 100 — 2026Sep · 102 mi · 116 ft/mi · AZSame distance · High altitude · Same month
- Plain Endurance Runs 100 Miler — 2026Sep · 103 mi · 193 ft/mi · WASame distance · High altitude · Same month
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