Park ranger Paul Zaenger tells Soldiers and Airmen from the Front Range community about the history of Black Canyon, Colo., During a snowshoe tour, part of a joint single soldiers and airmen camping trip to Black Canyon in the Gunnison National Park, Feb. 19, 2012. Park rangers tend 397 parks across the United States. The military and national parks service share a bond dating back to 1872, when the cavalry guarded and tended Yellowstone, the worldâ€™s first national park. Single Soldiers interested in participating in BOSS events should contact their company or battalion BOSS representatives, call the Fort Carson BOSS Office at (719) 524-2677, or attend one of the program's bi-monthly meetings held at the Foxhole at 10 a.m., the first and third Wednesday of every month.