The Lake Massabesic Watershed is one of the most fun rides in the southern New Hamphire area. The area is maintained by the Friends of Massabesic Bicycling Associaton, or FOMBA. There are over 13 miles of singletrack that tie into a large network of fireroads (about 20 miles in all). The singletrack is relatively technical, with lots of twists and turns, complete with your standard issue New England roots and rocks.
The trails are really well marked, and there's a map at the trailhead to help you plan your ride for the day. Defintely worth a drive from anywhere in the southern New Hampshire or Massachusetts MetroWest area!
From route 93 north or south take exit 7 and head East on route 101. Take exit 2 off of route 101 and go south on Hookset Rd. Take your second left on Depot Rd (shortly after crossing a RR bed). Go north on Depot a short distance until you see a parking area on your right.
Here's a link to the trail system, compliments of FOMBA: http://www.fomba.com/Map/fomba.pdf
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