U.S. Marines assigned to Engineer Company, Marine Wing Support Squadron 272, Marine Corps Air Station New River, N.C., use a excavator to clear and shape the side of a mountain to create a ditch to clear water and preserve the road being constructed near the U.S./Mexico border, Mar. 18. The Southwest border infrastructure support mission was coordinated by Joint Task Force North, the Department of Defense unit tasked to provide counterdrug support to the nation's federal law enforcement agencies.