Lance Cpl. Francisco A. Rivera, rifleman with 1st Battalion, 1st Marine Regiment, guards the perimeter of a landing zone during a noncombatant evacuation operation exercise at the West Wetlands Park in Yuma, Ariz., on May 7, 2010. The exercise is part of the current Weapons and Tactics Instructor course being held at the Marine Corps Air Station in Yuma. The city of Yuma regularly allows the Marines to hold exercises within its parks, which adds realism for the students. Since the Korean War, the Marine Corps has conducted at least 16 noncombatant evacuations, the most recent in Lebanon in 2006. Many of the pilots involved were trained in Yuma, said Col. Gary Thomas, commanding officer of Marine Aviation Weapons and Tactics Squadron 1, which teaches the course. Rivera is a 20-year-old native of Anaheim, Calif. The battalion is based in Camp Pendleton in California, and is training in Yuma for an upcoming deployment.