Hide Map


Parking is available at the trestle bridge 0.3 miles up NH-16 (Main Street) from the junction with US-2 in the center of Gorham. To reach the Power Island trail from the parking lot, cross the metal grating over the Androscoggin to Power Island on the Presidential Rail Trail. To get to the Undermine Loop, take the Presidential Rail Trail over the Androscoggin on the east side of Power Island.


The Power Island and Undermine Loop mountain bike trails are singletrack trails built for mountain bikes. The trails begin at a trestle bridge which offers spectacular mountain and river views. On Power Island (a man-made island formed by a canal that diverts water from the river to a hydroelectric dam), a single track loop twists and turns,  through dips and up rock garden climbs. The trail travels through pine groves and a variety of other forest types.

The Undermine Loop connects to the Power Island Loop via the Presidential Rail Trail. It is a winding roller coaster of singletrack and narrow bridges.

Other Information

These mountain biking trails are part of a 22-mile -- and growing! -- purpose-built mountain biking network maintained by the Coos Cycling Club, a non-profit organization dedicated to growing the mountain biking community through trail-building, group rides for all levels and ages, and vibrant events.

Trail Manager

The trail is maintained by the Coos Cycling Club. For more information, visit their website or contact: 

Coos Cycling Club
Gorham, NH 03581

Brookfield Renewable Power Company


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KML File

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GPX File

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Nearby Geocaches


Check for nearby geocaches to Power Island & Undermine Loop Mountain Bike Trails.

Leave No Trace Principle

Dispose of Waste Properly

Pack it in, pack it out. This goes for trash, leftover food, toilet paper, and hygiene products. If you brought it into nature, please bring it out.