Go to RTE 20 just East, I think, of Cherry Valley, and you'll see an old 2 span thru girder bridge. No tracks left or anything, but if you climb topside you can clearly see the old ROW from up there. If I am not mistaken, I believe that was built by NYS, and is one of the first girder bridges with horizontal ribs or something like that. I bet early spring, before the leaves grow in, would be a good time to check it out. If you go to Seward, at the intersection od RTE 165 and Slate Hill RD, there is an old Station on the North side of 165, and then south, there is a park that filled in what was left of the roadbed, formerly a sewer before the water system was put in in the mid to late 80's. South from there, down behind the highway department, you should still be able to find most of the ROW along the lake behind the HWY DEPT. If I remember, that roadbed leads to some old abutments. It may be private property now though. My Father once had a small hunting/summer place right there.
-- Mark