Marines with Company A, 1st Battalion, 3rd Marine Regiment, set up security at Sonora Pass during Mountain Training Exercise 2-15 at the Marine Corps Mountain Warfare Training Center, March 23, 2015. (Official Marine Corps photo by Cpl. Charles Santamaria/Released) - Marines with Company A, 1st Battalion, 3rd Marine Regiment, set up security at Sonora Pass during Mountain Training Exercise 2-15 at the Marine Corps Mountain Warfare Training Center, March 23, 2015. (Official Marine Corps photo by Cpl. Charles Santamaria/Released)