The New York, Ontario & Western Railroad took delivery of four (road numbers 401 through 404) 4-8-2s from the American Locomotive Company in 1922. These locomotives were designated as Class Y and had 27 x 28 cylinders, 69" drivers, a 200 psi boiler pressure, a tractive effort of 50,300 lbs and each weighed 317,000 pounds.

Another six "Mountains" (road numbers 405 through 410) followed from ALCO in 1923. They were designated as Class Y-1 and were essentially duplicates of the four Class Ys.

In 1929, ten more 4-8-2s were delivered from ALCO that were designated as Class Y-2 and assigned road numbers 451 through 460. These locomotives had 27 x 30 cylinders, 69" drivers, a 225 psi boiler pressure, a tractive effort of 60,620 lbs and each weighed 360,000 pounds.

The original Mountains had short tenders. The photo of 403 below shows it with the tender of an ex X class 2-10-2 locomotive. The 2-10-2s were scrapped because they were hard to maintain and hard to run -- they required two firemen. Instead of getting rid of the 2-10-2 tenders, the mountain type inherited the X's tenders and the mountain tenders went to a number of W class 2-8-0 locomotives. The 2-8-0s were remodeled with airpumps and many other things and were called W-2 class locomotives.

There are no surviving NYO&W "Mountains".