About This Race
Nestled in the Eastern Sierra Nevada at 8,000 feet elevation, Mammoth Trailfest offers runners a rare opportunity to experience alpine trail running in one of California's most stunning mountain settings. The town of Mammoth Lakes serves as both basecamp and finish line for this September celebration of high-altitude endurance, where crisp mountain air and sweeping vistas of jagged peaks create an unforgettable racing environment. The 50K course winds through diverse Sierra terrain, gaining 6,988 feet of elevation as runners traverse meadows, ascend rocky ridgelines, and navigate technical singletrack. With 90% of the route on natural paths, the race stays true to its mountain roots while remaining accessible to trail runners ready to step up their distance game. Six well-stocked aid stations provide essential support across the 12-hour time limit. Mammoth Trailfest attracts a field of 700 runners who appreciate both the physical challenge and the post-race mountain town atmosphere. The early morning start allows finishers to enjoy Mammoth Lakes' dining and lodging options, making this an ideal destination race for runners seeking high-altitude adventure without sacrificing comfort.
The 50K route unfolds entirely on natural paths and singletrack, showcasing the Eastern Sierra's dramatic alpine landscape. Runners begin in Mammoth Lakes and climb steadily through varied terrain including meadows, rocky sections, and technical trail features that demand both fitness and focus.
With significant elevation gain spread across the distance, the course challenges runners with sustained climbs while offering spectacular mountain vistas as reward. The technical nature of the terrain, combined with the high-altitude setting, creates a demanding but rewarding experience for prepared trail runners.
Elevation Profile
The course gains 6,988 ft over 31 miles, with the steepest section between mile 26–mile 26.
Course Map
Route shown is approximate and for illustration purposes.
Aid Stations
6 stations along the course
Aid Station 1
Aid Station 2
Aid Station 3
Aid Station 4
Aid Station 5
Aid Station 6
Practical Info
Late September in Mammoth Lakes typically offers crisp mornings with temperatures in the 30s-40s, warming to pleasant 60s-70s by afternoon, with minimal precipitation risk.
MMH - Mammoth Yosemite Airport
Mammoth Lakes offers extensive lodging from mountain resorts to vacation rentals, with most properties within walking distance of race activities.
Best For
Notable Features
The race's 8,000-foot elevation setting in the Eastern Sierra provides a unique high-altitude trail running experience rarely found in organized racing. The combination of technical singletrack, dramatic mountain scenery, and the intimate mountain town finish creates an authentic Sierra Nevada adventure that balances serious trail running with post-race relaxation opportunities.
Prepare for This Race
GEAR GUIDE
The Best Hydration Vests for Ultrarunning in 2026
A tested guide to the best hydration vests for ultra marathons and long trail races — from lightweight racing vests to high-capacity mountain packs.
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RACE GUIDE
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FROM THE TRAIL
How to Read an Elevation Profile (And Why It Matters More Than Distance)
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3 min read
GEAR GUIDE
The Best Hydration Vests for Ultrarunning in 2026
A tested guide to the best hydration vests for ultra marathons and long trail races — from lightweight racing vests to high-capacity mountain packs.
RACE GUIDE
The Best Trail Races for Your First Ultra
A thoughtful guide to choosing your first ultra marathon — what to look for in a course, how to evaluate difficulty, and five races worth considering.
FROM THE TRAIL
How to Read an Elevation Profile (And Why It Matters More Than Distance)
Elevation profiles reveal the true character of a trail race. Learn to read the shape of a course and understand what it means for your race day experience.