The Delaware, Lackwanna and Western rail lines that services from morris county thru Sussex County and into PA were closed down years ago. the rail lines coming up from the east diverged into two lines in Landing. the line that went west into Warren County remains active, but the other line was shut down. You can walk the trail 30 miles from Landing all the way to the Paulsinkill Viaduct which crosses the Delaware. Some time in 2010 NJT pretty much abandoned 29 apparently functional engines along the line somewhere (location not disclosed). They’ve been completely sealed up, except for one train which someone pried open. Along the way to them i found an old stone rail building. its completely sealed up and unless one has a blow torch, access isn’t possible.
more details on the history of the line closer from wikipedia
https://en.wikipedia.org/wiki/Delaware,_Lackawanna_and_Western_Railroad
The Lostinjersey Blog 
Posted by Marty on June 13, 2018 at 3:14 PM
The Paulinskill Viaduct does not cross the Delaware. It crosses the Paulinskill River.