This is not a MTB trail, a Rail-trail, or a road ride. What it is is unique, and an all weather ride.
Closed in 1968 this was part of the PA Pike. Although there were plans to turn it into a nice paved bike path. For now it has been left to nature to take care of. Although there is enough pavement left for road bikes, wider tires would be recommended. There are 2 tunnels 3/4 and 1 1/4 miles long, requiring the use of lights. For liability reasons the trail is "officially closed" but is really open. For more info and history.