"Union Pacific engine number 7002 pulling a passenger train called the "Forty-Niner," an all-Pullman hotel-on-wheels that made a round-trip from Chicago to San Francisco every six days (via Omaha, Cheyenne, Ogden, and Reno). In 1937, Diesel-powered "Streamliners" were still a rarity, and Union Pacific had no extra Diesels available for this new service, so they streamlined two existing steam locomotives to go with the lightweight cars. This burly 4-8-2 engine handled the train over the mountainous terrain between Cheyenne and Ogden, while a similarly-styled 4-6-2 was assigned to the more level territory between Cheyenne and Omaha. They were the only two steam locomotives given this styling and paint scheme. The train here is seen thundering eastbound up Weber Canyon, Utah, east of Ogden. They left Oakland Pier late yesterday morning, and they will be in Chicago early tomorrow afternoon. The designers and stylists got it exactly right-- this engine exudes determination, and unstoppability."
Colorized b/w photo by Imbued with Hues, from its FB page