Alco-Schenectady built this steam locomotive in March of 1921 originally as Chicago & North Western 4-6-2 Pacific #1636 (serial #62702, class E). The loco had several upgrades during the years (added stoker, Walschaert valve gear, increased boiler pressure) and in 1951-52, it was renumbered CNW #636. The loco lasted to the 10/11952 roster but disappeared after that, presumedly scrapped. This photo proves it made it into 1955. No photographer was listed for the photo which is now part of my rr collection.