This is a 21+ mile trail system that is an old railroad line. The trail begins in Franklin, MA on the edge of Franklin State Park and progresses through several towns and eventually ends in Douglas, MA. The Franklin entrance is available by taking exit 16 on I-495 and going towards Bellingham. After about 3 miles you take a right onto Grove Street and the entrance is about ¼ mile on the left. This section of the trail is quite rough for several miles but for a biker it is no real problem.
The second area they list for parking is in Douglas and is almost at the other end of the system. Take route 16W off Route 146 and drive about 5 miles until you get to route 96 and take a left. Entrance is about ¼ mile on the right. This section of the trail is in excellent shape in both directions for several miles.
Now I have listed two areas on entrance but the reality is this trail crosses numerous roads and at each there are gates at which you can park so you can do – as I have – and run this trail in sections. As you do each section you can explore as there are trails that break off in many places so if you are a runner this could be an adventure for a week or two.
If you wish to get this trail mapped here is a great site called traillink.com that will give you all the details you want.