Mammoth Trail Fest

Mammoth Trail Fest takes place in Mammoth Lakes, California, on September 25–26, 2026. The festival includes the Mammoth Triple, a three-day stage format that starts on September 25 and totals about 51 miles (82.1 km), and a 50K (31 miles) on Saturday, September 26. Both are trail events set in the Eastern Sierra, where Mammoth Lakes sits at high elevation, so the thin air is part of the challenge alongside the climbs.

The 50K is a strong option if you have a road marathon or shorter trail races behind you and want a first ultra in mountain terrain. The Triple suits runners who like the rhythm of stage racing: shorter daily efforts, recovery between days, and cumulative fatigue instead of one long push. Arrive a few days early if you can to adjust to altitude, and build your training around hill climbing, technical descending, and hiking. A 16-week block with weekend long runs on climbs and a couple of practice runs at elevation will pay off here.