 At the time of its construction, the airport held claim of having the third longest runway in the United States.From 1942 to 1945 the airport and surrounding 50,078-acre Southwestern Proving Ground were used by the U.S. Army to test small arms ammunition, 20 to 155 mm projectiles, mortars, rockets, grenades, and up to 500-pound bombs.The City of Hope received the airport facility in 1947.