Our Photo of the Day is truly special. Union Pacific is in the midst of a public relations tour de force with it's move of Pomona, California-based RailGiants former Big Boy, now UPP 4014*, but in years past, it was far from a lock as the home of big steam. Nearly every western US class 1 railroad had big steam in the 1940s. A World War and post-war boom stretched a national rail system to its limits and fed the need for big and bigger steam engines to move the freight (and passengers, imagine that!) over the mountain ranges that separate the bread basket of the world from the Pacific coast and her ports. These western railroads were interested in diesels, but knew that they would have to turn to tried-and-true steam technology.
3600-3609 and 3610-3619. The last of her class and only days away from her date with the scrappers torch (dear God, why?), this might be one of the last photos of the Rio Grande's largest, most powerful steam engines.◊
* - Union Pacific Passenger reporting mark avoids conflict with UP 4014, an active diesel on their roster, which is the same reason behind UPY. See UtahRails.net data on UP 4014, Note E. It seems no one wants to repeat the confusion over 844/8444/844.