 In 1998, Defense Special Weapons Agency, and selected elements of the Office of Secretary of Defense were combined to form the Defense Threat Reduction Agency (DTRA).In 1999, host-management responsibility transferred from the Defense Threat Reduction Agency once again to the Air Force until the Air Force mission ended in 2004 and the base was closed.In 1935, personnel from the US Navy's Patrol Wing Two carried out some minor construction to develop the atoll for seaplane operation.