Plattsburgh, Ny - i was born and raised in plattsburgh, ny and i know first hand there are a shit ton of rails around. Dowtown at the monument there are some super nice rails including c's s's and some straight ones, Also plattsburh state university has good rails on campus (next to harrington hall, around angel center, and the field house track. There are also a lot of random rails around the city.
Troy, Ny - I'm a freshman at rpi and i have already found a ton of rails in troy. The rpi campus is loaded. Some of the nicest rails are up near the athletic village which is conveniently located near the ice rink. Also check out downtown troy and the approach from the campus to downtown. Troy highschool has a lot of rails around their grounds as well.
and if your in upstate ny you mine as well check out burlington, vt.....they are loaded with rails