This envelope seems to be dated 1-67, a time when the railroad had gained a reputation of being anti-passenger. It had reduced service on most routes to at most one train a day, cutting the Shasta Daylight (which is nevertheless shown in the upper left on this envelope) in 1966. It also replaced the dining car on the Sunset Limited and certain other trains with an automat car which, passengers complained, ran out of food before the end of the trip.
It took these measures not so much because it was anti-passenger but because it was losing more money on passenger service than any other western railroad, and had been suffering those losses since shortly after the end of World War II. The cost-cutting measures can be seen in this envelope which is printed in one color only instead of in multiple colors like those of many other railroads.