I was down in the Catskills hiking the U&D from Highmount down to Phoenicia on the tracks, as much as could be done. We (Arnold Restivo) had a great hike of 15.5 miles, nearly all of it on the tracks. The bridge in Phoenicia is out, but we were able to travel across all the other bridges, one of them by scooting on our bellies on the rails. Close to Phoenicia is a washout with a creek completely eroding underneath the rails. Fortunately, there was a road nearby, otherwise it would have been difficult to cross. There are a good seven complete washouts of the tracks, most over 200', one over 500', and one at least 1000'.
Found the Pine Hill Crystal Springs Water Company ruins south of Pine Hill. Even after all this time, I found one bottle with an intact bottom, so we could read the entire name of the company. Found two sidings in Allaben -- one still has the switch in place, and the other has the switchstand ties and the switch ties, just to the east of where Station Road crosses to the north side of the tracks.
After we got to Phoenicia, I saw the narrow-gauge trestle on the south side of the river. Had dinner, then drove up to Grand Gorge. Searched around for the Delaware and Eastern, but didn't find anything I could definitely say "this is an attempt at grading a railroad". Possibly a railbed on the north side of Ferris Hill Road.
Cobleskill next, where I found a pedestrian underpass (blocked off because of a foot or so of water in the bottom) underneath the NS tracks, and on the east side of town, a pedestrian bridge. Then, on to the Cherry Valley Branch. Found one hidden bridge south of Sharon Springs, and another more obvious bridge over US-20. Walked across both of them.
Drove past the unfinished Fort Plains & Richfield Springs railroad and even after 140 years, and even with being unfinished, it stuck out like a sore thumb! On the south side of US 20, it's a 5' fill running across a field, and on the north side it's an 8' cut (which the neighbor is doing his best to fill in, but you can still see it). Chased that into Richfield Springs, but didn't find anything as stunningly obvious as at US-20. The Southern New York Railway running through town was more obvious, and the DL&W coming in from the west even more so. The DL&W seems to have been left in an odd state. The end of the tracks close to the active tracks still have rail! And all of the bridges have been left in place, all the way from Richfield Junction to Richfield Springs.
After that it was up to Herkimer and tracing the Adirondack Branch up to Remsen. Found four bridges left in place, and a few abutments for where others used to be. They just tore one out behind the Upper Canada Valley Central School, last summer.
Found Prospect and Prospect Junction and the spurs that went off of it. Found a tunnel through a high fill on Beecher Road northwest of Poland, AND a very small one-lane tunnel a half-mile northwest of that, both off NY-28.