These cards are not old. I purchased them while on vacation in Wyoming in 2006. What they are are reproductions of 1930s Works Progress Administration (WPA) posters done for the National Parks. To quote the back of the cards:
Between 1935 and 1943 the WPA's Federal Art Project printed over two million posters in 35,000 different designs to stir the public's imagination for education, theater, health, safety, and travel. Due to their fragile nature only two thousand posters have survived.
This is a nice example of ephemera being reissued/repurposed to our current times. To see more from the company that produced these click on the following link: Ranger Doug's Enterprises. I have nothing to do with this company, but I do think I'd like to purchase a few more cards and a poster to frame. Looking at the list of National Parks posters I'm happy to see I've been to all but 5 of the parks. I do love the National Parks, and I especially love the old lodges. We're very lucky to have these places. For me nothing can match standing at the base of a Sequoia tree looking towards the heavens. Nothing man-made can ever match it.
(a) circa 1939, artist unknown
(b) artists: Doug Leen and Mike Dupille
(c) circa 1939, artist unknown
To see the other cards in this collection and purchase the set click here.