U.S. Marines with Headquarters Battery, 11th Marine Regiment (11th Marines) set up camouflage netting for a Combat Operations Center aboard Marine Corps Air Ground Combat Center Twentynine Palms, Calif., April 20, 2013. 11th Marines conducted an artillery desert firing exercise to maintain their combat proficiency via realistic combat scenarios. (U.S. Marine Corps photo by Lance Cpl. Sean M. Searfus, 1st Marine Division/Released)