The Smarts Mountain Trailhead is located 5.1 miles east from Lyme on the Lyme-Dorchester Rd. This trailhead primarily serves the Appalachain Trail where it crosses. There is an information and an interpretive kiosk at this site. No other amenities are provided. Going north this section of the AT is called the Lambert Ridge Trail which ascends the scenic Lambert Ridge and then steeply climbs to the summit of Smarts Mountain in 3.9 miles. Going south the AT meanders for about 2.0 miles untill reaching another crossing of Lyme-Dorchester Rd. near the Dartmouth Skiway. The Ranger Trail also leaves this trailhead from the eastern end but is no longer maintained as an official trail.