MammothMarch Hudson Valley 2026

MammothMarch Hudson Valley is a 20-mile hiking challenge set in Harriman State Park, Southfields, New York, requiring completion within 8 hours. The course begins and ends at Lake Welch, offering a single-circuit day rather than a point-to-point route. Harriman State Park, New York’s second-largest, features 31 lakes, two beaches, public camping, streams, wildlife, and open views across the Hudson Valley. The route follows established park trails such as the Long Path, Beech Trail, and Arden Surebridge Trail. Organizers note this as one of the more challenging MammothMarch routes. It is designed as a fast, endurance hike, not a running race, focusing on covering significant distance on foot within the time limit. Participants are typically nature-lovers, hikers, and returning MammothMarch participants, aiming for a finish marked by accomplishment and satisfaction.