2025 Update
Permission to open registration has been granted by INF. Recent discussions with our permit administrators have given us confidence that we can move ahead with planning and registration for 2025 but a permit has not yet been issued and is not guaranteed.
** Please note: we will start registering the first 150 runners from the waitlist and have the hope to start 200+ runners total. Currently, ALL new registrations are being added to the waitlist. Once we are ready to move runners off the waitlist onto the entrants list, we will do so in the order that you are listed. You will receive an email invite, and have the opportunity to accept or decline your spot. Spots will be rolled down through the waitlist until we reach our runner capacity.
**In the event that all permits are not granted, we have two scenarios: we will either reroute the course around the section in question as best as we can - we do have a plan B contingency for that. The second scenario is that we are not able to find a suitable workaround despite exhausting all options, in which case we would issue entrants either a 100% refund or a 100% deferral with guaranteed entry into our 2026 race. We believe in full transparency, and we are going ahead with registrations only because we feel confident that we will be able to put on an amazing event in 2025. Thank you for your trust in us!
Course Description
The Mammoth is an epic 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 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
we are excited to 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
Runners Manual
visit our website
Pricing: $1495 early bird
Schedule of Events
September 25 — 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
September 26 — Race Start
* 4:30-5:45am Mandatory Spot Tracker pickup and gear check. YOU CANNOT START THE RACE WITHOUT YOUR SPOT TRACKER.
* 4:30 - 6am Coffee will be provided at the start line for all runners and crew
* 6am race start
September 28 – First Finishers Expected
* It’s year 1, so the course records remain to be set… but our projected times have our first runners finishing during the afternoon or early evening. 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!
September 30 – Race Ends @Village Plaza
* Award Ceremony will happen at 6pm. Come for awards, stay to cheer in our final finishers!
* Cutoff is 8:30pm, 110 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 1 – 6pm
* Any last drop bags must be picked up by 6pm in the Village Plaza. All remaining drop bags will be donated.
Project Mammoth
Event Cancellation
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, Cal-trans, and TOML 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 credit policy;
Prior to May 30: 75% deferral towards next year’s event and a guaranteed entry
May 30 to August 1: 50% deferral towards next year’s event and a guaranteed entry
After August 1 no deferrals accepted
Event's current local time: 4:22 PM PT
