Mammoth Trailfest

Mammoth Trailfest - September 25 - 27, 2026

Join the Mammoth Trailfest, a multi-day trail running experience in Mammoth Lakes, California, from September 25-27, 2026. This event is built by the community, for the community, offering an inclusive large-scale event on breathtaking terrain.

The festival includes world-class races, community-focused events, free live entertainment, storytelling, and local food. It aims to increase access to trail running through opportunity, education, and trail stewardship.

Races Offered:

• Dragon's Back Ascent: September 25, 2026, 9:00 AM. A run, hike, or walk from Twin Lakes Bridge up to the summit of Mammoth Mountain. (2.5hr cutoff)
• tenkay: September 25, 2026, 6:45 PM. A night trail run. (2hr 15min cutoff)
• 50K: September 26, 2026, 7:30 AM. A single loop course with 7,000ft of vertical gain. (12hr cutoff)
• Kid's 1K: September 26, 2026, 9:30 AM. A short race for children.
• 26K: September 27, 2026, 8:00 AM. A challenging loop course with a Mammoth Mountain summit finish. (7hr cutoff)
• Mammoth Triple: September 25-27, 2026. Combines DBA, 50K, and 26K.

Event Features:

• Limited edition trailfest. swag
• Unique finishers medal
• Post-race food and drink
• Professional live chip timing (50K/26K)
• Well-stocked aid stations with generous cut-off times
• 3-day festival with activations, talks, and performances
• Community shakeout runs
• Post-race party Sunday night
• Bus transport for Dragon's Back Ascent
• Free town transit

Registration Closes:

Wednesday, September 23, 2026, 11:59 PM PT

Waitlist and Special Entries:

Waitlists are available for sold-out races. Reserved spots are available for adaptive, 70+, and elite athletes.

Awards and Prize Money:

Top 3 female/male/non-binary/adaptive runners in each age group receive unique gifts. Prize money is offered for the 26K ($9,000), 50K ($9,000), and Dragon's Back Ascent ($3,700).

Cancellations and Refunds:

The event reserves the right to cancel or postpone due to force majeure. Refunds are not given in case of cancellation. Credits towards the following year's event are offered for runner withdrawals based on timing.

Age Requirements:

Participants must be 15 years or older for 50K, 26K, and Dragon's Back Ascent. Parental consent required for those aged 15-17.