Mammoth Trail Fest

Mammoth Trailfest - September 25-27, 2026

Mammoth Trailfest is a multi-day trail running event in Mammoth Lakes, California. The weekend features several races and community festival activities in the Village Plaza and on trails around Mammoth Mountain. Events include the Dragon’s Back Ascent, the 50K, the 26K, tenkay, a kids 1K, and a Mammoth Triple that combines three days of races. Prize purses are listed for the 50K, 26K, and Dragon’s Back Ascent.

Races, courses, and logistics

Distances and events:

• Dragon’s Back Ascent (summit finish)
• 50K
• 26K
• tenkay
• Kids 1K
• Mammoth Triple (DBA, 50K, 26K)

Courses use marked trails on USFS land and Mammoth Mountain terrain. The 26K and 50K include a summit section via Dragon’s Back Trail; the 50K is a single loop with multiple aid stations. Aid stations: DBA - no aid; tenkay - one aid; 50K - six aid stations; 26K - four aid stations. The event is cup-less; runners must carry their own cup or bottle. Chip timing is used for overall and age-group awards; gun time is used for prize money.

Safety, rules, and logistics

The event is high altitude on technical terrain; required gear is minimal but organizers recommend carrying a cell phone, at least 1 L of fluids, extra layers, and an emergency blanket. Poles are allowed. Littering, course cutting, and speeding by crews may lead to disqualification. Drop-bag transport is provided for DBA, 50K, and 26K with specific pickup and return locations. Medical support is available on course and an Emergency Action Plan is in place. Visit the organization's website for the most recent information.