During the Vietnam war and in its legacy, perhaps no group of men has created more interest or exhibited more heroism than the Soldiers, Marines, Sailors and Airmen of the  Studies and Observation Group.  Operating in secrecy and far away from the support of the vast military machine, they were the eyes, ears and the tip of the sword.

MACV-SOG was the joint service high command unconventional-warfare task force engaged in highly classified clandestine operations throughout Southeast Asia. It was given the title "Studies & Observation Group" as a cover. The joint staff was allegedly performing an analysis of the lessons learned to that point in the Vietnam War, but it was actually a special operations group with distinct command decision authority.

  In 1958 the South Vietnamese government created a secret special service directly under their president, which was re-designated the Vietnamese Special Forces Command in 1963. Special operations were conducted by this branch. The U.S. Central Intelligence Agency (CIA) supported and financed the operations. In April 1964 the government of South Vietnam created the Special Exploitation Service to take over these operations, whereupon MACV-SOG was established to assume the CIA's job of assisting, advising and supporting the new organization in the conduct of highly classified sabotage and psychological and special operations in North and South Vietnam, Laos, Cambodia and southern China.  MACV-SOG and the Special Exploitation Service (SES) were activated simultaneously. In September 1967 the South Vietnamese renamed the SES the Strategic Technical Directorate. With the draw down in U.S. personnel and operations, MACV-SOG was deactivated on 30 April 1972 and the Strategic Technical Directorate Assistance Team 158 was activated 1 May 1972 to take its place. This team was subsequently deactivated on 12 March 1973, and no other U.S. headquarters took its place.

  Originally headquartered in Cholon, it moved to Saigon in '1966. However, its air assets (Air Studies Group) were based at Nha Trang and its navy assets (Maritime Studies Group) were based at DaNang with its original Forward Operations Base (FOB 1). The Ground Studies Group launch sites were initially located at Hue-Phu Bai, Khe Sanh, Kham Duc and near Kontum. The MACV-SOG training center and airborne operations group were at Long Thanh. A Psychological Studies Group was located in Saigon with antenna stations at Hue and Tay Ninh.

MACV-SOG was assigned about 2,000 Americans, mostly U.S. Special Forces, and over 8,009 highly trained indigenous troops. It had its own air force (90th Special Operations Wing) comprised of a squadron of U.S. Air Force UH-IF "Green Hornet" helicopters, a squadron of U.S. Air Force C-130 aircraft, a covert C-123 aircraft squadron piloted and manned by Nationalist Chinese, as well as the South Vietnamese 219th "Kingbees" H-34 helicopter squadron. The U.S. Navy resources included SEAL's, Vietnamese Underwater Demolition Teams (UDT) and fast patrol boats. Ground forces included army military intelligence, psychological operations and some 76 ground RT mobile-launch teams, later MACV-SOG reorganized its ground strike elements into three field commands; Command and Control South, Central and North (CCS, CCC and CCN).

MACV-SOG had five primary responsibilities and the capability to undertake additional special missions as required. Primary responsibilities included: (1) Cross-border operations regularly conducted to disrupt the VC, Khmer Rouge, Pathet Lao and NVA in their own territories; (2) Keeping track of all imprisoned and missing Americans and conducting raids to assist and free them as part of the Escape and Evasion (E & E) mission for all captured U.S. personnel and downed airmen; (3) Training and dispatching agents into North Vietnam to run resistance movement operations; (4) "Black" psychological operations, such as establishing false (notional} NVA broadcasting stations inside North Vietnam; (4) "Gray" psychological operations as typified by the Hue- Phu Bai propaganda transmitter. MACV-SOG was also entrusted with specific tasks such as kidnapping, assassination, insertion of rigged mortar rounds into the enemy ammunition supply system (which were set to explode and destroy their crews upon use) and retrieval of sensitive documents and equipment if lost or captured through enemy action. MACV-SOG was often able to use the intelligence it gathered for its own internal purposes as well as for high command special activities.

Command and Control North (CCN) was formed by MACV-SOG in late 1967 as an expansion of its Da Nang Forward Operations Base (FOB) which included launch sites established as early as 1964 at Hue-Phu Bai, Khe Sanh and Kham Duc, CCN, always the largest of the three MACV-SOG field commands, was commanded by a lieutenant colonel.  It was assigned  conduct of classified special unconventional warfare missions into Laos and North Vietnam.  

CCN was organized along the lines of CCC and was composed of Spike recon teams (RT), Hatchet forces and lettered SLAM companies.  Missions into North Vietnam were initiated as early 1 February 1964 under OPLAN 34A.  Operations into Laos commenced in September 1965 as part of Operation SHINING BRASS, renamed PRAIRIE FIRE in 1968.  By this time  MACV-SOG had at its disposal two battalions of American-led Nung tribesmen as reaction forces capable of performing large combat missions.

CCN often operated in conjunction with CIA trained Meo tribesmen of Gen. Vang Pao.  In 1971 the Laotian operations were given the code name PHU DUNG, and in March of that year MACV-SOG created Task Force I Advisory Element to replace its three field commands. This task force was located at DaNang.