Mammoth March Hudson Valley 2026

Mammoth March Hudson Valley is a 20-mile endurance hike through Harriman State Park, starting and finishing at Lake Welch Beach, with an eight-hour time cap to complete the single-loop course. Participants pick a start wave, with the earliest groups heading out from 7:30 a.m., and aid stations along the route carry cut-off times that walkers must beat to continue. There are no obstacles and nothing technical about the terrain; the challenge is simply covering the distance on foot inside the clock, which makes it a natural target for hikers and ruckers building toward full-day efforts.