Mu Gia Pass
Encyclopedia
The Mu Gia Pass is a mountain pass in the Annamite Range
between northern Vietnam and Laos, located 90 km northwest of Đồng Hới, Vietnam. The pass is 418 m above sea level and connects Route 15 from Tân Ấp in Vietnam to Route 12 in Khammouane Province in Laos.
The pass was the principal point of entry into the Ho Chi Minh Trail
through Laos. A CIA
landscape analysis prepared in February 1966 described Route 15 as threading "its way upstream along a narrow, steep-sided valley. To the left rise dog-toothed limestone peaks, to the right is a flat-topped plateau. Dense tropical rain forest covers the entire area, almost frustrating aerial observation. The road is carved out of the steep hillside, for in most places there is not enough room for both road and stream in the constricted bottom of the ravine". Due to its difficult geography, the pass was identified as a choke point and as a result was heavily bombed first as part of Operation Barrel Roll
and later as part of Operation Rolling Thunder
and Operation Commando Hunt
. By March 1966, it was estimated that 75% of all truck traffic into Laos went through the pass.
On 12 April 1966, 29 B-52s attacked the pass for the first time in the largest bombing mission since World War II, using a combination of subsurface and delayed action bombs over a 5 km section, but the pass was not closed by landslides as had been hoped for. A second B-52 strike took place on 26 April but the damage was repaired within 10 hours and convoys were seen using the pass the next day. A CIA report noted that the "Communists will spare no effort to keep it open". Despite frequent bombing, the United States Air Force
and United States Navy
were never able to put the pass out of operation for any sustained period of time. The North Vietnamese Army
(NVA) also constructed several bypass roads around the pass to the east and west of Route 12 in Laos and later a series of petrol, oil and lubricants (POL) pipelines through the pass. The NVA progressively built up their air defences around the pass, first installing smaller calibre anti-aircraft artillery
(AAA), then larger calibre (100mm) AAA, by 1966 more than 300 AAA sites had been identified around the pass. By 1972 SAM-2
missiles covered approaches to the pass, forcing B-52s and gunships to keep their distance reducing the interdiction effort.
Annamite Range
The Annamite Range or the Annamese Mountains is a mountain range of eastern Indochina, which extends approximately through Laos, Vietnam, and a small area in northeast Cambodia. It is known in Vietnamese as Dãy Trường Sơn, in Lao as Xai Phou Luang , and in French as the Chaîne Annamitique...
between northern Vietnam and Laos, located 90 km northwest of Đồng Hới, Vietnam. The pass is 418 m above sea level and connects Route 15 from Tân Ấp in Vietnam to Route 12 in Khammouane Province in Laos.
The pass was the principal point of entry into the Ho Chi Minh Trail
Ho Chi Minh trail
The Ho Chi Minh trail was a logistical system that ran from the Democratic Republic of Vietnam to the Republic of Vietnam through the neighboring kingdoms of Laos and Cambodia...
through Laos. A CIA
Central Intelligence Agency
The Central Intelligence Agency is a civilian intelligence agency of the United States government. It is an executive agency and reports directly to the Director of National Intelligence, responsible for providing national security intelligence assessment to senior United States policymakers...
landscape analysis prepared in February 1966 described Route 15 as threading "its way upstream along a narrow, steep-sided valley. To the left rise dog-toothed limestone peaks, to the right is a flat-topped plateau. Dense tropical rain forest covers the entire area, almost frustrating aerial observation. The road is carved out of the steep hillside, for in most places there is not enough room for both road and stream in the constricted bottom of the ravine". Due to its difficult geography, the pass was identified as a choke point and as a result was heavily bombed first as part of Operation Barrel Roll
Operation Barrel Roll
Operation Barrel Roll was a covert U.S. Air Force 2nd Air Division and U.S. Navy Task Force 77, interdiction and close air support campaign conducted in the Kingdom of Laos between 14 December 1964 and 29 March 1973 concurrent with the Vietnam War.The original purpose of the operation was to serve...
and later as part of Operation Rolling Thunder
Operation Rolling Thunder
Operation Rolling Thunder was the title of a gradual and sustained US 2nd Air Division , US Navy, and Republic of Vietnam Air Force aerial bombardment campaign conducted against the Democratic Republic of Vietnam from 2 March 1965 until 1 November 1968, during the Vietnam War.The four objectives...
and Operation Commando Hunt
Operation Commando Hunt
Operation Commando Hunt was a covert U.S. Seventh Air Force and U.S. Navy Task Force 77 aerial interdiction campaign that took place during the Vietnam War. The operation began on 11 November 1968 and ended on 29 March 1972...
. By March 1966, it was estimated that 75% of all truck traffic into Laos went through the pass.
On 12 April 1966, 29 B-52s attacked the pass for the first time in the largest bombing mission since World War II, using a combination of subsurface and delayed action bombs over a 5 km section, but the pass was not closed by landslides as had been hoped for. A second B-52 strike took place on 26 April but the damage was repaired within 10 hours and convoys were seen using the pass the next day. A CIA report noted that the "Communists will spare no effort to keep it open". Despite frequent bombing, the United States Air Force
United States Air Force
The United States Air Force is the aerial warfare service branch of the United States Armed Forces and one of the American uniformed services. Initially part of the United States Army, the USAF was formed as a separate branch of the military on September 18, 1947 under the National Security Act of...
and United States Navy
United States Navy
The United States Navy is the naval warfare service branch of the United States Armed Forces and one of the seven uniformed services of the United States. The U.S. Navy is the largest in the world; its battle fleet tonnage is greater than that of the next 13 largest navies combined. The U.S...
were never able to put the pass out of operation for any sustained period of time. The North Vietnamese Army
Vietnam People's Army
The Vietnam People's Army is the armed forces of Vietnam. The VPA includes: the Vietnamese People's Ground Forces , the Vietnam People's Navy , the Vietnam People's Air Force, and the Vietnam Marine Police.During the French Indochina War , the VPA was often referred to as the Việt...
(NVA) also constructed several bypass roads around the pass to the east and west of Route 12 in Laos and later a series of petrol, oil and lubricants (POL) pipelines through the pass. The NVA progressively built up their air defences around the pass, first installing smaller calibre anti-aircraft artillery
Anti-aircraft warfare
NATO defines air defence as "all measures designed to nullify or reduce the effectiveness of hostile air action." They include ground and air based weapon systems, associated sensor systems, command and control arrangements and passive measures. It may be to protect naval, ground and air forces...
(AAA), then larger calibre (100mm) AAA, by 1966 more than 300 AAA sites had been identified around the pass. By 1972 SAM-2
S-75 Dvina
The S-75 Dvina is a Soviet-designed, high-altitude, command guided, surface-to-air missile system...
missiles covered approaches to the pass, forcing B-52s and gunships to keep their distance reducing the interdiction effort.