Second set of 4 sets of map pictographs for U.S. national park maps. PD US Government - National Park Service, U.S. Dept. of the Interior
rest of sets:
http://openclipart.org/media/files/johnny_automatic/6741
http://openclipart.org/media/files/johnny_automatic/6757
http://openclipart.org/media/files/johnny_automatic/6765
