The Mammoth
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The Mammoth : Mammoth Lakes, California
The Mammoth is a loop ultramarathon that starts and finishes in Mammoth Lakes, California. The route circumnavigates a caldera formed about 760,000 years ago and connects small mountain communities. The course passes alpine lakes, abandoned mines, fall foliage, dense pine forest and the Glass Mountains. Runners also move through high desert terrain, expanses of volcanic rock, large Jefferey pine forest and the tufa towers of Mono Lake. The route includes summit sections on Mammoth Mountain that reach 11,053 feet and offer extensive panoramic views.
The event operates on National Forest land under special use permission from the Forest Service and runs with a secured permit. Organizers aim to start 250 participants and manage a reserved pool of spots with a waitlist process for openings. Entry pricing is listed as $1595 for early bird through February 28th. Spot Trackers are mandatory equipment for competitors and the event enforces medical and gear checks as part of check in.
Prize money is offered to male and female podium finishers with amounts of $5,000 for first place, $3,000 for second and $2,000 for third. The 2025 edition recorded a 74% finish rate despite storms and significant summit snow. The event has a stated overall cutoff of 108 hours. Refund and deferral policies vary by date, with refund percentages and deferral options specified for withdrawals prior to listed deadlines. Visit the organization's website for the most recent information.
