Most ticket envelopes are pretty ho-hum, but this one stands out. For one thing, what looks like a mailing label on the front is actually a cellophane window with pictures of the Empire Builder and Western Star locomotives printed on the inside, a little Easter egg for passengers to find when they remove their tickets from the envelope.

Click image to download a 719-KB PDF of this ticket envelope.

The envelope also features pictures of mountains in Glacier Park and images of a skier, horseback rider, Blackfeet Indian, and fly fisherman — all things people would see if they visited GN’s hotels in and around the park. The other side has a map of the GN through which you can faintly see the pictures of the locomotives.

A date codes says this was printed in May, 1951. The Western Star and Mid-Century Empire Builder began operating on June 3, 1951, so many of the lucky passengers who rode either of those trains would have been given their tickets in an envelope like this one.