USSF MACV-SOG SFD B-56 project Sigma Recon Team patch Tham Bao

Project Sigma:
Special Recon was initiated under orders from General Westmoreland in August of 1966 was initially set up to achieve the task of rescuing US Military Operatives held prisoner in Cambodia.
Over the following years the Project was to grow to Eight Recon Teams (Special Recon) and three Commando Companies and in late 1967, under the command of MACV undertook additional Long Range Intelligence Gathering activities in conjunction with the POW search missions.

"Tham Bao" is Vietnamese for "Gather Intelligence"

SFOD B-56 Project Sigma had 8 reconnaissance teams, 3 commando (reaction) companies and a 168-man Nung security company. The personnel for the commando companies, and reconnaissance teams were either ethnic Cambodians or Nung mercenaries. SFOD B-56 Project Sigma teams abducted POWs back from the enemy in the Fish Hook area of war zone C. An enemy telephone line was located, tapped, and conversations recorded. Other teams placed electronic surveillance devices, set mechanical ambushes, and a host of electronic devices to hinder and harass the enemy along infiltration routes into South Vietnam. SFOD B-56 Project Sigma's Road Runner Teams were transferred over to SFOD B-57 project Gamma in 1967. SFOD B-56 Project Sigma also assisted and acted as forward reconnaissance elements in several Black Jack operations which were conducted in its area of operations. In November 1967 operational control of SFOD B-56 was given directly to MACV whereupon B-56 was placed under the control of the II Field Force. SFOD B-56 Project Sigma was relocated to Ban Me Thuot in 1969. American elements leaving Vietnam on the 2nd of May 1971.