Located a few miles north from the border of the United States and Mexico, the U.S. Coast Guard has maintained a continual presence in San Diego since 1935. It was in May of that year that a single air detachment, led by Cdr. Elmer F. Stone, began operating out of a commercial hangar at Lindbergh Field. From those humble beginnings, a base was constructed on 23 acres of tidelands adjacent to the airstrip and eventually formed into Sector San Diego. Through the years, their units and missions have evolved as new technology and changing world events dictated new missions for the Coast Guard. Today Coast Guard Sector San Diego stands as a model of interagency cooperation for the Department of Homeland Security as the Coast Guard works with other federal agencies to protect San Diego's maritime domain.