Ben Nephew posted the route:
The Tully Trail is an isolated trail loop in North Central Massachusetts.
More information on the property can be found here:
The trail section heading west from Tully Lake is closed, the trail now continues down the dirt road to start the singletrack at the trailhead on Mountain Rd.
The loop consists of singletrack and carriage roads with some short road sections. It only has about 3000' of climbing, but some of the singletrack is extremely technical and/or difficult to follow due to the fact that the trail sees very little traffic. During my recent run, I only saw three people over 3.5 hours. It is listed as 22 miles, but I am guessing the actual mileage is closer to 24 miles.
GPS track for my run of 3:19:24:
Results of a supported run of the Tully Trail may be seen here: tullytrailrun.blogspot.com/p/results_15.html