Course map, elevation profile & surface
Fly the course
Follow the route over 3D terrain, mile by mile.
Race-day light
For a 6:15 finish (an estimate) · starting 7:00 AM Sep 12. Dark means the sun below civil twilight.
Climbs
7 climbs · 2,434 ft totalbiggest firstAid stations as published on the course file
| Aid station | Mile | km |
|---|---|---|
| A AS1 | 5.1 | 8.3 |
| A AS2 | 9.6 | 15.4 |
| A AS3 | 12.2 | 19.6 |
| A AS4 | 15.7 | 25.3 |
| A AS5 | 19.0 | 30.6 |
| A AS6 | 24.4 | 39.3 |
| AS7 | 29.6 | 47.6 |
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 12 at the start
Typical = the median of 2016–2025 for Sep 12 ±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 72°F at the start, with a low of 51°.
| Year | Start °F | Rain | Wind |
|---|---|---|---|
| 2026 Sep 12 | 72°/51° | dry | 11mph |
race-day weather from the Open-Meteo historical archive (ERA5) at the start line.
Reviews what runners who have been there say
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About this course
Boulder Field 100 50K — 2026 covers 29.6 mi (47.7 km) with 3,150 ft of elevation gain. That is about 106 ft per mile of climbing, and 3,143 ft of descent. The course tops out at 1,959 ft and bottoms out at 1,004 ft. There are 6 aid stations on course; the longest stretch between aid is 5.5 mi. The profile has 7 sustained climbs; the biggest is the climb to AS4, +807 ft over 5.4 mi at 2.8% on average (steepest stretch 12%). Race day is September 12, 2026, starting at 7:00 AM; the sun rises at 6:41 AM and sets at 7:19 PM. Typical race-day weather at the start: a high of 74°F and a low of 56°F, with a 34% 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
- Oct 29, 2026Added to the catalog
Races like this one close in distance, climbing, terrain, altitude, weather and season
- Epic East Gate 50K — 2026Sep · 31 mi · 111 ft/miSame distance · Similar climbing · Same month
- Lost Soul Ultra 100 Mile — 2026Sep · 31 mi · 125 ft/mi · AlbertaSame distance · Similar weather · Same month
- Standing Boy Trail Festival 50K — 2026Sep · 31 mi · 112 ft/mi · GASame distance · Similar climbing · Same month
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