The unit was in existence from April 14, 1942 to July 12, 1945. During most of that time, it funded and coordinated various resistance groups made up of the Kachin peoples of northern Burma. One resistance force was known as the Kachin Rangers and was under the command of Carl F. Eifler though often the term Kachin Rangers has been used to describe all Kachin Forces raised during the war by the Americans in Northern Burma.
In July 1942 twenty OSS men moved in and set up headquarters in Assam. No operations of any significance occurred until the end of 1942. Starting in 1943, small groups or individuals were parachuted behind Japanese lines to remote Kachin villages, followed by a parachute supply drop. The Americans then began to create independent guerilla groups of the Kachin people, calling in weapons and equipment drops. Once settled, the groups undertook a variety of unconventional missions: ambushing Japanese patrols, rescuing downed American pilots, and clearing small landing strips in the jungle. They also screened the advances of larger allied forces, including Merrill's Marauders.
Eifler held the rank of Colonel when he was discharged in 1943 because of injuries. Lt. Col. William R. Peers took over command. At the end of the war, each Kachin ranger was given the CMA (Citation for Military Assistance) Award. The medal was actually the result of a mistake. One OSS officer, reading a radio message that advised him how to reward heroic Kachin action, had misinterpreted the word for "comma", "CMA", as signifying some kind of medal. Unable to leave the Kachins empty-handed, the medal was quickly created by OSS and delivered.
OSS Detachment 101 - highlights several declassified reports and documents obtained from the archives of the Central Intelligence Agency, and the Combined Arms Research Library
