Combat Training: A Marine purses his lips and squeezing his eyes shut as he is dragged from a mock booby trap in the “Pit and Pond” obstacle during the endurance course at the Jungle Warfare Training Center, Okinawa, Japan, April 19, 2015. The endurance course is the final event Marines participating in jungle warfare training must face, trudging through roughly five miles of Okinawa jungle through 30 obstacles. Marines got creative in shuffling their squad mates beneath loose Plexiglas, avoiding contact with the “booby trap” at all costs. If any portion of the pane is touched, all Marines in a five-meter radius are considered casualties and have to go back through the Pit and Pond. The Marines are with Company L, 3rd Battalion, 3rd Marine Regiment. The Hawaii-based battalion is attached to 4th Marine Regiment, 3rd Marine Division, III Marine Expeditionary Force as part of the unit deployment program. U.S. Marine Corps photo by Sgt. Matthew Callahan