The Canyons Endurance Runs™ by UTMB®
The Canyons Endurance Runs™ by UTMB® – 50K
Downtown Auburn
Race guide
Updated 19 July 2026
The Canyons Endurance Runs by UTMB 50K is the middle distance of the Canyons weekend, a 50 km out-and-back-style route that starts and finishes in Downtown Auburn, California and threads the American River canyon system on the region's historic single-track. It carries 1324 m of climbing with a high point of only 585 m, so this is not a race decided by altitude but by repeated steep drops to the river and the climbs back out of it. Expect a course that keeps giving and taking elevation, with the hardest work saved for the return leg. It is an ideal step up for runners who have handled the shorter Canyons distance and want a genuine ultra on the same iconic canyon trails.
The course and terrain
The route starts in Downtown Auburn at 387 m and quickly descends to Confluence (Confluence - 1) at 6.4 km and 171 m, dropping over 200 m to the river almost immediately. From there it climbs to Clementine at 11.5 km (453 m), then continues out along the canyon rim to Drivers Flat at 25.1 km (522 m), the high shoulder of the course near its 585 m high point. The second half reverses the pattern, plunging to Mammoth Bar at 37.9 km and just 193 m, then returning to Confluence (Confluence - 2) at 43.9 km (183 m) before the final climb back up to the Downtown Auburn finish at 50 km (386 m). With everything sitting between roughly 170 m and 585 m, the challenge is entirely in the repeated canyon descents and ascents, not in thin air.
Where the race is won and lost
The decisive terrain is the back half. After the long, runnable pull out to Drivers Flat at 25.1 km (522 m), the course throws its steepest drop of the day, losing more than 320 m down to Mammoth Bar at 37.9 km (193 m). That descent is fast and free, but it trashes quads that then have to handle the climb from the second Confluence checkpoint (183 m, 43.9 km) back up roughly 200 m to the Auburn finish. The finishing climb is where the 50K is truly decided. It comes after 44 km of accumulated canyon vertical, so runners who spend everything on the Mammoth Bar descent will struggle up the final ascent to the line. Ration your downhill effort in the second half specifically so you can climb back to Auburn strongly.
How to pace and fuel it
The 50K is governed by a single hard deadline: the finish cut-off at Sat 17:00. With no tight intermediate gates listed, the pacing plan is your own to build, which makes it easy to start too fast on the early descent to Confluence. Resist that. Run the first drop under control, hike the climbs efficiently, and keep a steady rhythm out to Drivers Flat so you reach the turn with legs intact. Use the aid points at Confluence, Clementine, Drivers Flat and Mammoth Bar to stay on top of fluids and calories, and carry enough water to cover the longer climbs between them. Because the return leg concentrates the toughest climbing at the end, front-load your fuelling: take in energy consistently through the middle of the race so you are not trying to claw calories back on the final ascent to Auburn.
Conditions to expect
As with the shorter Canyons events, heat is the headline condition rather than altitude. The route repeatedly bottoms out below 200 m at Confluence and Mammoth Bar, where the canyon floor holds warm air, and the climbs back to the rim are the most exposed stretches of the day. With the finish cut-off on a Saturday afternoon, the hardest late climbing tends to fall during the warmer hours, so build your hydration strategy around that reality. Underfoot this is the classic Auburn canyon single-track: runnable but technical on the descents, with rocky and rooty sections that reward confident, controlled downhill running. Strong descending and the discipline to save something for the final climb matter far more here than flat-ground speed.
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Checkpoints & cut-offs
✓ Course data verified against the official source (2026-07-17) · official source
0 km · 387 m · —
6.4 km · 171 m · —
11.5 km · 453 m · —
25.1 km · 522 m · —
37.9 km · 193 m · —
43.9 km · 183 m · —
50 km · 386 m · Sat 17:00
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