Ever wonder about the mechanics of moving mail through America via national parks? You’re in luck: Opening June 9 and running through March 25, 2018, Smithsonian’s National Postal Museum in Washington, D.C., presents Trailblazing: 100 Years of Our National Parks. The exhibition, which marks the centennial of the National Park Service, takes a fascinating look at the role played by the National Park system in the transfer of mail, including mail sent and received by persons of Japanese ancestry who were incarcerated in California and Idaho facilities during World War II, and artifacts and photographs on loan from Grand Canyon, Sequoia, Petrified Forest and other national parks. Also included: postcards sent from Hawaii that bear scorch marks from having been thrust by tourists into active lava flow crusts before mailing. Among the museum’s permanent collections — one of the world’s most comprehensive assemblages of stamps and philatelic material — are an 1851 mail coach built in Concord, N.H.; a dogsled used by mail carrier Ed Biederman (1861-1945) on his 160-mile route between Circle and Eagle, Alaska (complete with moose hide lashings); authentic Pony Express trappings including a leather “mochila” mail knapsack; and the famous gold and diamond Clum Locket. Open daily from 10 a.m.–5:30 p.m. (except for Christmas Day), the museum is located at 2 Massachusetts Ave., across from Union Station.