A topographic map of karst-riddled terrain in Laos, retained as part of the documentation for the search-and-rescue effort for 'Boxer 22,' a downed aircraft or aircrew during the Vietnam War. Maps like this guided rescue helicopter crews and forward air controllers through some of the most treacherous terrain along the Ho Chi Minh Trail, where limestone caves and dense jungle sheltered both downed airmen and enemy forces. Project: 218834