That line from PA up through Corning NY to Lyons was one of the few places that the NYC used "mainline" Articulated/Mallet engines. The NYC had a whole class of articulated steam Loco's built specifically for that line (circa 1920's). These replaced doubled headed steam loco's.
(Edit), I believe the NYCRR "NE" class compound articulated loco's are the ones specially built for the "coal hauling" lines of the NYCRR coming North out of PA and connecting to the "Mainline" at Lyons NY. These were built from 1917 to 1922 ? There was about two dozen of them, they replaced about 4 dozen other loco's at the time;
http://rrpicturearchives.net/showPictur ... id=5046097
The NYCRR also had a dozen or so articulated loco's used as hump yard pushers. (End of edit)
Of course the "Water Level Route" never went out of the way to advertise their "mountain railroading" to the public.
Much of the coal was high quality coal for use in railroad steam loco's and was shipped across Lake Ontario to Cobourg in Ontario. Apparently Eastern Canada had very little high quality coal to mine for use in the railroad loco's.
My Father (NYCRR Loco Engineer) ran on that line from Buffalo to Lyons to Corning and return (circa 1972-1974). The crew would overnight and return the next day. This was an "Inter-Divisional" run so the jobs were split evenly between Buffalo engine crews and Corning engine crews. About every 3 months (IIRC) the crews would swap. IE for 3 months all the trains were handled by Buffalo based crews. Then for the next 3 months all the trains were handled by Corning based crews.
This was a union deal dictated to the railroad. They counted the exact number of trains operated by the "other division" crews and once the allotted number of trains had been operated by the Buffalo crews the Corning crews would run the very next train. Sometimes when the "swap" occurred Dad got "deadheaded" home from Corning to Buffalo in a taxi cab.... Got paid for a full trip, and the Corning folks running the train got paid for the the same full trip. And people wonder why the NYC/PC went bankrupt.....
Dad said when getting on his train in Corning in the summer and fall evenings he always had a good flashlight in hand because the rattlesnakes would like to shimmy up against the nice warm rails at dusk to stay warm....
Rattlesnakes occur in "pockets" all around the southern parts of NY State. They were exterminated in many areas but since they don't travel very far the pockets of rattlesnakes that survived never expanded their population much into areas where they had been killed off.....