U.S. Marines with Alpha Company, 1st Battalion, 6th

U.S. Marines with Alpha Company, 1st Battalion, 6th Marine Division, 2nd Marine Division (MARDIV), patrol through mountainous terrain to get into position to execute a rock cliff assault at landing zone sardine rock, during basic mountain training for Mountain Exercise 5-15 at the Marine Corps Mountain Warfare Training Center, Bridgeport, Calif., Sept. 17, 2015. Marines participate in a month-long field exercise focusing on core mission essential tasks such as assault climbing, animal packing and small unit movements, to strengthen expeditionary high altitude warfare tactics in a mountainous environment against a hybrid threat, as they prepare for world-wide deployment. (U.S. Marine Corps photo by Cpl. Kelly L. Street, 2D MARDIV COMCAM/Released)