MammothMarch New Hampshire

MammothMarch New Hampshire returns to Allenstown, New Hampshire on August 29th, 2026. The event will take place in the expansive Bear Brook State Park, a scenic and challenging course that stretches over 20 miles through heavily forested trails, marshes, bogs, summits, and ponds.
Bear Brook State Park is known for its natural beauty, with lush greenery and varied terrain. On race morning, expect to find runners gathered at the park’s main entrance on Route 108, just north of Allenstown village, where the atmosphere will be one of anticipation and excitement among participants who are ready to conquer this demanding yet rewarding route.
Since its inception in 2019, MammothMarch has grown into a beloved event for both long-time runners and newcomers. Over the years, it has attracted hundreds of participants from across New Hampshire and beyond, all united by their love for nature and community. The race supports local conservation efforts and scholarships, making every step on this journey meaningful.
The 20-mile course will lead through some seldom-visited areas within Bear Brook State Park, offering a unique experience that combines the thrill of competition with exploration of New Hampshire’s wilderness. Runners can expect to navigate various terrains from gentle forest paths to rocky outcrops and water crossings, all set against the backdrop of rolling hills.
On race morning, anticipate temperatures in the mid-20s Celsius (68°F) with a comfortable humidity level around 75%. The average wind speed is expected to be about 8.4 km/h (5 mph), providing a steady breeze that may add some extra challenge but won't detract from the overall experience.