This is a work in progress. The entire corridor when done will be over 100 miles long making it the longest single rail trail in New England. However, it is not really traversable right now from Northampton to Boston in a safe fashion. Click on this link to go to information about the currently open sections.
The corridor has about 25 miles +- that are currently open. There is another 60 +- miles that are in various categories of 'protected' status. [owned by various state agencies, or municipalities, land trusts or conservation commissions.]
About 10 +- miles are owned by private entities such as railroads or utilities. Only a few miles have been sold off to adjacent landowners in various places along the way and most of this can be reclaimed eventually. Otherwise, only a small fraction has been lost forever, [floods washing away RoW or other earth changing events].
Though the RoW of the former railroad is viewable and walkable [or even mountain bikeable] in many sections, we do not recommend this as the ownership of the land is never discernible and trespassing on private property is never a good thing to do. Trespassing will also impede our efforts to develop the trail.