This is a 22 mile out and back on one of the most difficult sections of trail in New England. If the entire 114 mile Metacomet Monadnock trail is too long, but the 12 mile 7 Sisters trail race is too short, then you can connect sections 7 and 8 of the MM for a challenging 22 mile.
The run starts on Harris Mountain Road before climbing Long and Norwottuck mountains. The middle 12 miles is the 7 Sisters course, and I turned at the Skinner State Park Road at the end of the singletrack. The first and last 5 miles are relatively easier, but they didn't feel that easy towards the end. The trail is technical singletrack with steep climbs and descents over the 7 Sisters course.
My run took 3:42:40 with the run over the 7 Sisters in about 2:05.