One of the kids wrote the card to Grandma.
This, I don't doubt, was "state of the art" in nineteen-seventy something. Looks to me as though the designer had not yet awakened from his psychedelic nightmare.
(Can you even imagine traveling with four kids and going to places like Ogallala, Nebraska and Jonesboro, Arkansas? Again, thanks to Lidian for the Motel Postcard idea.)