U.S. Marine Corps Pfc. Francesco A. Fara, left, and

U.S. Marine Corps Pfc. Francesco A. Fara, left, and Lance Cpl. Daniel L. Bruce, right, both riflemen with Bravo Company, 1st Battalion, 6th Marine Regiment, 2nd Marine Division (MARDIV), provide security at a machine gun post located at the top of landing zone mean peak, during the final field exercise of Mountain Exercise 5-15, Marine Corps Mountain Warfare Training Center, Bridgeport, Calif., Sept. 23, 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)