**theMAMMOTH operates on permitted area and uses authorized facilities located on the National Forest and under special use permission from the Forest Service. 2026 permits pending. Permission to advertise granted from USFS
WELCOME HOME
theMAMMOTH was born out of a desire to showcase the remarkable beauty of the Eastern Sierra, increase local economic impact during shoulder season, and provide a peak life experience with the community and quality that you know and love from trailfest.
in 2025 we had an incredible 74% finish rate despite multiple storms and over a foot of snow on the second summit. we are here for the cutoff chasers and course record breakers. when the time is right we would love the opportunity to host you - tim and team
VOLUNTEER SIGNUP OPENS 1/5/26
If you'd like to volunteer with us this year, please sign up through our scheduling form: volunteer with us
We've got sweet vollie perks like exclusive swag and race credits. Email us for more info: themammoth@mammothtrailfest.com
Runners Manual
visit our website for full event details, required gear, policies, etc.
Pricing: $1595 early bird through Feb 28th
Course Description
The Mammoth is an unreal footrace through the Eastern Sierra, starting and finishing in Mammoth Lakes, California. This breathtaking loop connects small mountain communities while circumnavigating a 760,000 year old caldera. Your route will take you along pristine alpine lakes, abandoned mines, golden fall foliage, and dense pine forests before heading into the remote beauty of the Glass Mountains. Fragrant sage fills the air as you climb through high desert terrain and rolling hills. You’ll traverse vast expanses of volcanic rock, our world’s largest continuous Jefferey pine forest, and the great Tufa towers of Mono Lake. The race is bookended with summits of Mammoth Mountain, offering unreal 360° views from 11,053 feet of your entire journey
Prize Money
as always, we offer prize money to our f/m podiums.
$5,000: first place female and male
$3,000: second place female and male
$2,000: third place female and male
Schedule of Events
October 1st — Mandatory Race Check-in
* 12-6pm check in, in the Village Plaza at Mammoth Lakes
* Headshots for Spot Tracker, mandatory medical check in
* Runner briefing at 5:30pm
October 2nd — Race Start
* 7:00-8:30am Mandatory Spot Tracker pickup and gear check. YOU CANNOT START THE RACE WITHOUT YOUR SPOT TRACKER.
* 7-9am Coffee will be provided at the start line for all runners and crew
* 9am race start
October 4th – First Finishers Expected
*Follow along with the live tracker and race updates during the race to know what’s going on, and come out to the Village Plaza to cheer them in!
October 5th - OA Podium Awards Ceremony
*11:00am start/finish line - celebrate the queens and kings of Mammoth!
October 6th - Village Cutoff
*JOIN US AS WE CHEER IN OUR FINAL FINISHERS!
* Cutoff is 9:00pm, 108 hours
* Drop bags will be available for pickup in the Plaza on a rolling basis, as aid stations close. Any drop bags sent to the final few aid stations will not be returned until after those AS have closed, so please plan accordingly if you have to leave early.
October 7 – 6pm
* drop bags must be picked up by 6pm in the Village Plaza. All remaining drop bags will be donated.
Event Cancellation, Deferrals, Refunds
trailfest reserves the right to cancel or postpone THE MAMMOTH due to a force majeure event, including, but not limited to, acts of nature (e.g., storm, fire, smoke, earthquake, flood), acts of government, strike, lockout, civil disorder, war or commandeering by any agency of government, pandemics, epidemics, and quarantine restrictions, or other unsafe conditions, as solely determined by trailfest. Please be aware that wildfires are a serious risk in the area. Permits to hold the event are also subject to USFS, LADWP, BLM, Mono County, Cal-trans, TOML and law enforcement agency approval and they have the right to revoke permits at any time. Secondary to fixed costs of organizing this event, refunds will not be given in the event of cancellation. Practical efforts to fairly resolve unforeseen cancellations will be made.
In the case of runner withdrawal prior to the event we will honor the following refund/credit policy, refunds will be less the ultrasignup fee
Prior to June 1: 75% refund or 100% deferral towards next year’s event and a guaranteed entry; June 1 to June 30: 50% refund or 75% deferral towards next year’s event and a guaranteed entry; July 1 to July 31: 25% refund or 50% deferral towards next year’s event and a guaranteed entry; After August 1 no refund or deferrals accepted
*Withdrawal from ultrasignup will automatically apply deferral credit towards following year per policy stated above.
*If requesting refund, please email themammoth@mammothtrailfest.com
*deferrals are good for following year only
Project Mammoth
Event's current local time: 9:21 PM PT
