Green Monster 25K & 50K Trail Challenge

Green Monster 25K & 50K Trail Challenge is held in Wellsboro, Pennsylvania, on October 11, 2026. Three trail formats start in waves: the 50K (31 miles) at 7:30 a.m. with about 7,800 feet of climbing, the 25K (about 15.5 miles) at 9:00 a.m. with about 4,000 feet, and the 15K (about 9.3 miles) at 10:45 a.m. with roughly 1,700 feet of elevation gain.

The elevation figures tell you what kind of race this is: the 50K packs more climbing than many mountain ultras, and even the 15K is a genuine hill race. Wellsboro sits near the Pennsylvania Grand Canyon, and the terrain in the state's north-central forests is steep and often technical. The 50K suits experienced trail runners looking for a hard, hilly ultra, the 25K is a strong objective for someone with a trail half marathon behind them, and the 15K makes sense as a first mountain race. Training should center on climbing: weekly hill repeats, long runs that seek out sustained ascents and descents, and power-hiking practice for the steepest grades. Give the 50K 16 to 18 weeks, and expect cool October conditions with the fall foliage near its peak.