“The fight for control of the vital artery emerged as an important front in the long-running war and led to the conflict spilling over into both Laos and Cambodia.”
Certainly the famous network of jungle and mountain roadways used by Hanoi to secretly smuggle men and materiel from the communist north into South Vietnam rivals in scope the 25,000 miles of trenches dug along the Western Front in World War One, Hitler’s vaunted “Atlantic Wall” or the Allies’ Mulberry Harbour of D-Day.
The trails spanned most of the 1,500 kilometers (900 miles) between the North Vietnamese capital and the Mekong Delta. And at the peak of the fighting in South East Asia, it provided safe passage for hundreds of thousands of regular troops and VC insurgents, plus enough materiel, fuel and ammunition to supply the communist war effort in the south for more than a decade.
Not surprisingly, U.S. commanders in Indo China were just as obsessed with choking off the Ho Chi Minh Trail as the North Vietnamese were with keeping it open. In fact, the fight for control of the vital artery emerged as an important front in the long-running war and led to the conflict spilling over into both Laos and Cambodia.
Here are ten amazing facts about this hotly contested highway.
The Ho Chi Minh Trail was not a single road, but rather a vast web of criss-crossing and intersecting pathways, tracks and thoroughfares totalling 16,000 km (9,500 miles). If somehow unravelled and laid end to end, it would span the breadth of the Eurasian landmass from Lisbon to the Bering Strait. It snaked down from the north, past the Demilitarized Zone (DMZ) and through the dense and rugged forests of neutral Laos and Cambodia, running parallel to the Vietnamese border. A series of exit roads branched off from the main line at various points into South Vietnam. It’s from these openings that infiltrators and supplies poured into the territory controlled by the Saigon government.
Named by the Americans
Ironically, it was the U.S. forces that gave the Ho Chi Minh Trail its name, which referenced the long-time North Vietnamese leader. The communists called it Ðuong Truong Son or the “Truong Son Road” for the mountain region through which it passed.
Built upon a tangle secret foot and bicycle paths hacked out of the jungles by Viet Minh forces during the earlier French Indo China War, construction of what became the Ho Chi Minh Trail began in earnest in 1959. Hanoi initially dispatched more than 400 engineers and labourers connect the trails and blaze more pathways southwards. Almost immediately, guerillas used the network to infiltrate South Vietnam.
By 1961, U.S. intelligence estimated that more than 5,000 insurgents were reaching South Vietnam annually using the route. 
From Jungle Path to Paved Road
For the next 16 years, work never stopped on the Ho Chi Minh Trail. Throughout the 1960s, thousands of engineers toiled in horrendous conditions to widen and expand the pathways to accommodate wagons, small vehicles and even heavy trucks. Alternate and dummy routes were carved out of the jungles to confound enemy intelligence. To prevent the trails from being becoming bogged down during the summertime monsoon season, gravel, corduroy and even pavement were used along key segments. Early in the war, it could take a VC infiltrator up to six months to travel the trail from north to south by foot.  But within a few years, that time was reduced to weeks, or even days, thanks to an innovative and sophisticated system of truck relays organized and run by the 559th Transport Group, the 24,000-man unit of the North Vietnamese Army assigned to manage the network.
A Triumph of Logistics
As the work on the trails continued, supply depots, troop barracks, tunnel complexes, bunkers, hospitals and logistical command and control centers known as binh trams were set up at regular intervals by an army of 40,000 workers – and all of it masked by the dense impenetrable tropical canopy. In fact, it’s been reported that soldiers and vehicles could travel the whole of the network without ever emerging from the cover of the jungle. Entire battalions of North Vietnamese infantry were assigned to defend the route’s flanks against enemy recon units, while key areas bristled with anti-aircraft defenses.
The Infiltration Super Highway
As the war continued, Hanoi used the system to secretly funnel ever more men, supplies and military hardware into South Vietnam. In 1964, as many as 12,000 communist troops and irregulars had infiltrated enemy territory by way of the trail, while up to 30 tons of supplies a day were trickling into the south along the jungle passageways.  In 1966, between 60,000 and 90,000 combatants had marched south via its roads and pathways.  In the lead up to the 1968 Tet Offensive, the trail enabled the communists to pre-position some 200,000 troops and 81,000 tons of weaponry at key points in South Vietnam.  By the war’s end, more than a million tons of materiel had moved through the network.
Severing the Artery
American forces worked ceaselessly to disrupt the Ho Chi Minh Trail. Beginning in 1964, U.S. warplanes hammered its routes round the clock using everything from A-1 Skyraiders to B-52 bombers. In 1965, as many as 1,000 sorties were flown against key waypoints in North Vietnam, as well as Cambodia and Laos. By late 1968, that number swelled to more than 500 strikes a day.  While the air campaigns hampered the communist supply lines, men and material continued to flow south, mostly undercover of darkness. Efforts to cut the line using ground troops met with only limited success.
With bombing and ground operations having achieved only limited success, the Pentagon began exploring unconventional (and sometimes rather outlandish) methods of disrupting the Ho Chi Minh Trail.
In 1968, U.S. military intelligence air-dropped 20,000 battery-powered sensors, some disguised to look like animal droppings, along the length of the system. The small devices could detect sounds and vibrations of any movement, be it human or vehicular. “We wired the Ho Chi Minh trail like a drugstore pinball machine and we plugged it in every night,” said one U.S. intelligence official.  Signals from the devices were transmitted to recon aircraft, which could then direct air strikes onto enemy troop concentrations. The $1 billion dollar program, known as Project Igloo White, was considered a waste of time money and resources.
That same year, the U.S. Air Force undertook an ambitious scheme to literally wash away the trail by way of man-man rainstorms. Between 1968 and 1972, C-130 transport planes seeded the clouds over South East Asia with rain producing silver iodide and lead iodide designed to produce torrential downpours. The project, codenamed Popeye, did produce higher volumes of precipitation, but the trail still remained open.
Finally, there was Project Commando Lava, an outlandish scheme in 1967 to drop 120 tons powered soap onto the pathways following a rainfall. After making contact with the wet ground, the compound would foam up creating an impenetrable morass of goo. The plan was shelved after the low-flying transports used to deposit the mixture fell prey to enemy ground fire.
The Last Caravan
By the time American combat troops were withdrawing from South East Asia, the Ho Chi Minh Trail had evolved into a fully paved, four-lane highway that ended just northwest of Saigon. By 1969, the communists had even installed an eight-inch-wide plastic pipeline system that pumped fuel to NVA and VC units operating in the south. The supply network was in use right up the end of the war. In fact, many of the troops and vehicles that encircled and finally overran the South Vietnamese capital moved in from the north along the trail.
Following the war, the Hanoi regime built a two-lane national highway astride the famous supply route. The Vietnamese government plans to expand it into an eight-lane national thoroughfare.
Forty years after the war’s end, the remnants of the original Ho Chi Minh Trail still remain intact. In fact, they’ve become a popular destination for hikers and off-road-bikers.
(Originally published July 31, 2015)