Angeles Crest 100K
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About the race
The Angeles Crest 100K and the Red Box Mountain Marathon are inaugural trail races on the Angeles Crest 100 Mile Front Range course in the San Gabriel Mountains. Both events use trails from the current AC100 Front Range route and are presented as a preview of that terrain and course character. The Angeles Crest 100K begins and finishes in Altadena. Runners will encounter sustained climbing, technical trail, exposed ridgelines, remote mountain terrain and long descents.
The top three male finishers and top three female finishers in the 100K will each earn a Silver Ticket into the Angeles Crest 100 Mile Endurance Run, subject to the AC100 mile registration and eligibility requirements. The Red Box Mountain Marathon follows the opening section of the Front Range course from Altadena toward Switzer, Clear Creek, Josephine and Red Box, finishing at Red Box after approximately 26 rugged mountain miles. This is a point to point race; transportation details will be published in the official runner instructions. Field limits are specified for each race: the 100K is limited to 250 runners and the Mountain Marathon to 100 runners. Final course measurements, elevation profiles, cutoff times, aid station information, required equipment and transportation plans will be published as race preparations are completed.
Registration closes March 17, 2027. Visit the organization's website for the most recent information.
