[8-B] Lieutenant Colonel Moody noted that the Vietnamese Marines seldom were involved in the actual construction of strategic hamlets. This task was normally left to the civil authorities in the area who more often than not used the local population as a labor force. (_Moody Comments._) In the closing days of April, the JGS ordered Lieutenant Colonel Khang to form two infantry battalions and an artillery element into a provisional brigade for immediate assignment to II Corps. There the Vietnamese Marines were to join elements of the 2d and 25th ARVN Divisions for a multi-regiment thrust into the rugged mountains just south of the I Corps-II Corps border. Code named BACH PHOUNG XI, this offensive was to penetrate the Do Xa, a Viet Cong base area never before entered by government forces. Centered in that portion of the Annamite Mountains where the borders of Quang Tin, Quang Ngai, and Kontum Provinces converged, the Do Xa had been under Communist control since the early stages of the French-Indochina War. In this remote, inaccessible mountainous zone the Viet Cong reportedly had built-up extensive staging areas and training camps. Prisoner interrogations obtained throughout the early 1960s revealed that many North Vietnamese soldiers entering the South’s northern provinces had infiltrated the Do Xa before moving into the densely populated coastal lowlands of Quang Tin and Quang Ngai provinces. Additionally, the area was thought to contain the Communist military headquarters for Military Region 5 (MR-5). After alerting his 2d and 4th Battalions, a pack howitzer battery, a reconnaissance platoon, and a headquarters element, Khang flew with Lieutenant Colonel Moody to Pleiku for planning conferences with Major General Nguyen Khanh and his II Corps staff. The concept of BACH PHOUNG XI, Khang and Moody learned, called for U.S. Marine and Army helicopters to lift ARVN infantry and artillery elements into positions which would form a loose ring around the suspected center of the Do Xa base area. The ARVN units would then begin contracting this ring in stages, whereupon the provisional Marine brigade would be helilifted into its center, the heart of the Do Xa, to search for Communist camps. To control the entire operation General Khanh would establish a corps headquarters forward at Plateau Gi, a Montagnard village located on the southern edge of the operations area, about 25 miles northeast of Kontum.