Xépôn Xépôn , also known as Tchepone and Sepon , was a village in the Sepone administrative district of Savannakhet Province in the country of Laos . It was located approximately east of the intersection of the Sepon River and the Banghiang River . It was the target of Operation Lam Son 719 in 1971 , an attempt by the armed forces of South Vietnam and the United States to cut the Ho Chi Minh Trail . The operation failed , and the village was wiped out . Geography . Xépôn was located on the north bank of the Sepon River at an altitude of . The countryside was mountainous , broken , and covered in subtropical forest . Average rainfall each year was . In the rainy season ( July to September ) , rainfall could be a month . The Sepon River runs in a trough between two natural , high ridges . The trough itself is only wide . This geologic feature begins just west of the town of Khe Sanh in Vietnam . The northern ridge ends near Xépôn , while the southern ridge continues for another . A shallow bowl forms between the ridges ( permitting north - south traffic out of the valley ) near the Laotian town of Ban Dong . The southern ridge turns southwest ( followed by Route 9 on the north side and the Banghiang River on the south side ) , and ends near the town of Mường Phìn . However , the best break in these ridges occurred at Xépôn , where land traffic could move east , southeast , and southwest . History . Xépôn was most likely settled in the 1500s by settlers from the Muong Thanh Valley in Vietnam . During the period when France ruled Laos as a colony , the French constructed Route 9 . Opened about 1930 , Route 9 ran from the major city of Savannakhet on the Thai - Laotian border in the west across the entire country to the border with Vietnam in the east . It met National Route 9 , a major Vietnamese highway , at the border . Just a few meters upriver from where the Sepon and Banghiang rivers met , Route 9 crossed the Banghiang . The bridge here had three spans , and could accommodate much traffic . Xépôn also played a role in anti - colonial movements in Laos . In the aftermath of World War II , a Laotian independence movement , the Lao Issara , formed to seek national independence . Thao Ō Anourack , a native of Xépôn , was appointed commander of all Lao Issara forces in the district . Initially successful , French forces seized the capital of Vientiane by April 1946 . Most of the Lao Issara fled to Thailand . In September 1946 , however , several Laotian leaders met in the Vietnamese city of Vinh and , with the sponsorship of the Viet Minh movement , formed the Committee for Lao Resistance in the East to carry on the fight for indepencence . Thao Ō Anurak was one of the founding members of the committee . Due to its location near the ridge breaks and two major rivers , the village of Xépôn is estimated to have had about 1 , 500 inhabitants in 1960 . Just five years later , half of the residents had fled due to war . Air base . During the 1950s , the French military built a military airfield near Xépôn . The airfield was located about northwest of the village on the south bank of the Se Nam Kok River . At in length , the dirt airstrip was the largest in Savannakhet Province , and the second largest airfield of any in the nearby South Vietnamese provinces . The Royal Lao Army ceased defending the airfield in 1961 , and it fell into North Vietnamese hands . Xépôn proved to be a critical point on the Ho Chi Minh Trail . The trail was a series of supply routes along through Laos which North Vietnam used to supply forces of both the People ' s Army of Vietnam ( PAVN ) and the Viet Cong guerrilla forces , both of which were operating in South Vietnam . Route 9 provided a quick way to move supplies east . The light Vietnamese trucks could also cross the Banghiang River at Xépôn which , although across was just deep most of the year , and then travel further south . This made Xépôn the chokepoint for almost all motorized traffic passing through Mu Gia Pass , the main Ho Chi Minh Trail entry point into Laos . Only Route 23 , which led south from Mường Phìn , provided a good alternative . The North Vietnamese invested Xépôn in December 1958 , and built a large , heavily defended military base there to help defend the area . Operation Lam Son 719 . American officials believed that Xépôn was abandoned by 1970 . In 1971 , Xépôn was the focus of Operation Lam Son 719 . On February 8 , I Corps of the Army of the Republic of Vietnam ( ARVN ) — supported by long - range artillery , bombers , and helicopters provided by the United States armed forces — invaded Laos . The objective was Xépôn , where the air base was to be made operational . The goal was to interdict the Ho Chi Minh Trail for three months . The operation was a complete failure . Instead of attacking at the end of the rainy season ( when North Vietnamese troops would be very undersupplied ) , the attack began three months later ( long after their supplies had been improved ) . I Corps officers ( many of whom were suspected of North Vietnamese sympathies ) were told of the operation at the last minute . Press reports about the operation leaked almost as soon as the attack began , alerting North Vietnamese and Viet Cong forces . Logistical planning by the South Vietnamese and the U . S . was poor . Nearly 8 , 000 ARVN troops were lost , and more than 100 U . S . helicopters . Nearly $ 1 million in military equipment was abandoned as ARVN forces fled Laos in a near - rout on March 24 . It is not even clear that Xépôn was even occupied by the North Vietnamese any longer . American officials reported large quantities of food , ammunition , and other supplies cached in and around Xépôn , and that ARVN troops and American aircraft destroyed them . But other reports indicate that , while supply caches were destroyed , Xépôn had already been abanoned by the North Vietnamese in favor of other routes . Operation Lam Son 719 destroyed Xépôn and left it deserted . Modern Xépôn . During the Laotian Civil War , the Pathet Lao captured Xépôn in early May 1975 . The Pathet Lao toppled the constitutional monarchy of Laos on December 2 , 1975 . In the years after the new government took power , a new town using the name Xépôn was built on the site of the old French airfield . By 1998 , the new town had a population of about 35 , 600 . The site of Old Xépôn ( Xépôn Kao in Laotian ) has few remains . A new temple was constructed on the site of the town wat , and a safe and pile of bricks marks the town ' s former bank . Gold was discovered near Xépôn by Conzinc Riotinto of Australia / Rio Tinto Group in 1993 . More gold deposits were identified by Oxiana in 2000 . Known gold deposits total of gold . Industrial gold mining began in late December 2002 . Extensive copper deposits were discovered north of Xépôn in 2000 . Construction of a large copper mine , the most technologically advanced in Asia , began in 2003 . Copper production began in 2005 . These mines produced of copper , of gold , and of silver in 2009 . The same year , the company Lane Xang Minerals Limited began a US $ 60 . 4 million expansion of the copper mine designed to raise yearly production to . As of 2010 , the copper and gold mine at Xépôn was Laos ' largest private business , and it ' s largest private employer .