Again, The Railroadians' book will best give you the details you are looking for so you should seek it out. In the meantime, remember the Erie once owned the NYS&W-WB&E, I believe up to the late 30's, so the indication would be correct.
Also, in the area rail lines were planned, laid, ripped up and relaid, forgotton, and relaid, etc. Owners and charters changed, and some of the lines were built on former gravity railroad right of ways. If you are looking at topo maps, and others, the initial date of the map may be right with corrections and additions made at later dates; these later changes should be noted or footnoted someplace. If not, then the former statement applies.
Most important though, is for you to find a copy of the book.
Also, in the area rail lines were planned, laid, ripped up and relaid, forgotton, and relaid, etc. Owners and charters changed, and some of the lines were built on former gravity railroad right of ways. If you are looking at topo maps, and others, the initial date of the map may be right with corrections and additions made at later dates; these later changes should be noted or footnoted someplace. If not, then the former statement applies.
Most important though, is for you to find a copy of the book.