I've seen it mentioned in the NY/NJ/DE/PA buy thread by a few people. From what I understand most of it is basically a dirt road. Depending on who still looks in that thread, you may find a few there.
I've followed the northern sections. Back roads / dirt roads. Anything trail like seems to have been closed in the north.
Found a rail gun testing area. And Buttermilk Falls.
Some beautiful areas up there and I love to drive, so worth it for that aspect.
anyway, most of the 'trails' in TNJT are paved back roads, some are dirt. The only trail worth while up north was Paradise Rd. That is closed permanently. Last time I drove it was in 2016, entered from the west and didn't see any postings. I went to the east end last Nov and it was obvious you are not allowed to go down the trail.
Pick the orthoimagery base layer and you can zoom in to see the tracks. They go feet from a dewling in that little parcel. The road is on the eastern edge of the county.
Best open trails I've found are unmaintained class 4 rds in VT and class 6 rds in NH. Have to keep up with the gov maps, though, as unmaintained rds can go private.