Union Pacific inaugurated the City of Los Angeles, City of Portland, and City of San Francisco in 1935, with the City of Denver coming in June, 1936. This booklet isn’t dated, but at one point it refers to the train in the future tense: “The Streamliner ‘City of Denver’ will provide fast, safe, economical, and luxuriously comfortable service daily.”
With just five-and-one-half revenue cars–two 50-seat coaches and three-and-one-half sleepers with a total of 82 beds–this train’s capacity was fairly low. Considering it cut nine hours off the schedule of heavyweight trains, UP must have frequently sold almost every seat and berth. Yet unlike the City trains to the West Coast, the railroad charged no extra fare on the City of Denver. The train’s non-revenue spaces included the diner/lounge, the rear half of the observation car, and the unique Frontier Shack, which filled the rear half of a baggage-tavern car.