Between Korea and Vietnam the development of surface-to-air missiles brought a tremendous change in both the technology and organization of ground-based air defense in the United States Marine Corps. The USMC's first surface-to-air missile was the Terrier (operational in the Navy in 1956), and the unit to which it belonged became known as the Medium Antiaircraft Missile Battalion. On 1 May 1956 the Marine Corps Guided Missile Test Unit (MCGMTU) consisting of six officers and 45 men was established at (NOTS) Naval Ordanance Training Station, China Lake, CA and on 1 June 1956 was redesignated the 1st MAAM Bn and relocated to MCB Twentynine Palms, CA. Previously, Marine personnel had served at NOTS since1951 with the 1st Provisional Marine Guided Missile Battalion. In 1958, this unit replaced the light antiaircraft artillery battalion which consisted of quad 50 cal machine-guns mounted on half-tracks, and twin 40mm AA guns mounted on tank chassis. Before the Terrier was even three years old, the USMC replaced it with the HAWK missile system which the Raytheon company develop in the late 1950's and the 1st MAAM Bn was redesignated as the 3rd Light Anti-Aircraft Missile (LAAM) Battalion.