Ive recenlty online learned that there used to be a 9th ave elevated Polo Grounds shuttle that ran in the bronx and is possible to see on foot, altough I can not seem to find it.
From what I know of, the First Stop on the 9th Ave EL would have been Sedgwick Ave, which is now I believe the Major Degan express way. Ive tried to look for the overpass of the Cat walk above the highway, but cant seem to find the visible part of the Platform underneath the highway. Was it removed when they built the highway?
The second stop on the EL would have been Jerome-Anderson Aves. From the 
Train going North from 161 St, I can see the station Partially. But when I go to the station in front of a shop, I cant see to find the entrance to the station and was wondering if there was another way inside the station.
Im not sure what would have been the Next Stop on the 9th Ave EL, but Im sure it connected with the Train near Yankee Stadium. And as I know of, the 159 St Yard is completley gone. What remains of the 9th Ave el, please tell me! I would like to explore it.