Opened in 1923,[1] it follows the Wapack Range north-south for 21 miles (34 km), between Mount Watatic in Ashburnham, Massachusetts, and North Pack Monadnock mountain in Greenfield, New Hampshire.

It also goes over Temple Mountain, and through Miller State Park, Binney Hill Wilderness Preserve, and the Wapack National Wildlife Refuge, as well as numerous privately owned parcels of land.

The trail was born in a conversation in the summer of 1922 at the Shattuck Inn in Jaffrey, New Hampshire between Allen Chamberlain, formerly president of the Appalachian Mountain Club, and Jaffrey farmer Albert Annett while overlooking the Wapack Range, then known as the Boundary Mountains.

Later, Albert brought the idea to fellow farmers Frank Robbins and Marion Buck of Rindge, New Hampshire.

On Labor Day in early September, a 18-mile (29 km) race[5] coordinated by Paul Funch covers the southern part of the trail.