View on Youtube
This is a pair of separately named rail trails, the Northampton Rail Trail and the Norwottuck Rail Trail. The first runs between Northampton's Look Park at Bridge Road to where it summarily ends at King Street. The second starts less than a quarter mile east of this and continues on, including an extension, to Warren Wright Road east of Amherst. There is the idea of linking the two. At present, one has to take a significant detour, typically via Bridge Street / Route 9 in (busy) downtown Northampton, to get between the two. No signage exists in this regard.
The most notable thing about this trail is that it is heavily shaded throughout its length. This does limit the view, however. There is a dedicated plank bridge over the Connecticut River and an underpass under Routes 9 and 116, among others. There are services, including a bike shop (according to a trailside sign) along the way but the heavy trailside foliage can make them hard to spot.
Beyond these, there is the typical number of cross street crossings. Also, the paved surface has the unfortunately also typical poor surface with much broken pavement. Serious cyclists would avoid this path. One more thing about the pavement is that in a nod to the watermelons (green on the outside, red on the inside), broken used glass has been mixed into some long stretches of the asphalt. Of course, this is a hazard to bicycle tires as well as making it indistinguishable between this and 'fresh' broken glass on the trail.
After the reasonable climb up into near Amherst center and past the Amherst College athletic fields, the trail has a lot of downgrade heading east. It then levels out through the swampland surprisingly common in central Massachusetts. This attracts a number of nature viewing walkers. There is a completed extension taking the trail from Station Road to Warren Wright Road. A turn left/north here leads to climbing and eventually out to Route 9.