Above is an oversize (5-1/2" X 7-5/8")postcard advertising Northern Pacific Railway's North Coast Limited. This is a view of the Lewis and Clark Traveller's Rest Buffet-Lounge car, designed by industrial designer Raymond Loewy. The Lewis and Clark-themed interior of the Traveller’s Rest car was added in 1955. Below is a standard size postcard of the train's Vista-Dome interior.
The images used on these postcards were also used in the 1956 magazine ad for the Vista-Dome North Coast Limited shown below (source: Wikipedia). According to the ad, this was the only train between Chicago and the North Pacific Coast that offered the attention of a friendly Stewardess-Nurse.