I don't generally collect postcards much later than the '20s, but I found one for a quarter yesterday that I could not resist. Here's a card with a June 29, 1950 postmark from Sulphur, Oklahoma showing the Lincoln Bridge in Platt National Park. Now I'm fairly knowledgeable about the National Park Service, but I had never heard of Platt NP. Why? Because it no longer exists! In 1976, the national park was converted into the Platt Historic District of Chickasaw National Recreation Area. There are other instances of national parks being renamed or redesignated, but this is the first time I've come across a postcard of one!