There was a story in the local paper about the National Park Service's trading card program. I've tried to find some more info on the program, especially a checklist, but the results of my search have been weak.
It appears that various National Parks and Sites will provide some cards to young visitors. The cards might be an extension of the Civil War cards to commemorate the 150th anniversary of the start of that conflict.
Some of the NPS websites that contain info about the cards are: