The last time anyone documented a saola, the observer was a machine. A movement-triggered camera in the forests of central Vietnam took the photograph in 2013, and since then there has been nothing: no confirmed sighting, no carcass, no track anyone could stand behind. Fewer than three hundred are thought to survive, possibly as few as fifty, and the animal has been called critically endangered for so long that some biologists now use the word inevitable. Nakai-Nam Theun National Park exists in large part because the saola might still be walking through it.
Science met the saola in 1992, when survey teams working in Vu Quang in Vietnam found remains that belonged to nothing described before - a slender forest bovid with two long, nearly straight horns. WWF announced the discovery that July; the formal description followed in 1993. Vu Quang National Park shares a border with Nakai-Nam Theun, the same range viewed from the other side of the ridge, and the saola's entire known world amounts to a strip of the Annamites perhaps five thousand square kilometres across. Much of what kills it is not even aimed at it. Saola blunder into wire snares set for wild boar, sambar and muntjac raiding crops, and they are hunted directly as well, for meat and furs and traditional medicine. Conservation teams have pulled more than 26,000 snares out of saola country, and the forest keeps filling up with more.
The park covers roughly 4,270 square kilometres of the Annamite Range and the Nakai Plateau below it, spanning Khammouane and Bolikhamsai provinces. Its eastern edge is the crest of the Annamites, which is also the Vietnamese border, and the terrain there is rugged enough to have done most of the protecting. Phou Laoko, at 2,286 metres, is the high point. Everything drains one way: the Nam Kata, Nam Xot, Nam Mon, Nam Noy, Nam Pheo and Nam One all feed the Nam Theun, which gathers them and carries them southwest onto the plateau.
Climb here and the forest changes beneath your feet. Dry evergreen forest holds the Annamite slopes below 1,800 metres, threaded between 1,400 and 1,700 metres with stands of Fokienia hodginsii, a cypress-like conifer valuable enough that its commercial worth is also its danger. Above 1,800 metres the canopy turns wet and montane, dominated by oaks, Castanopsis and Lithocarpus. Push past two thousand metres and the trees give up their height entirely, shrinking into stunted, rhododendron-dominated cloud forest where everything drips. Nakai-Nam Theun holds the only known population of Vietnamese white pine in Laos, along with the threatened conifer Cephalotaxus mannii. Surveys since 1994, run jointly by the Wildlife Conservation Society, the Lao Department of Forestry and the IUCN, are what established all of this.
More than four hundred bird species have been identified in the park and its northern extension. That is not merely the highest count in Laos - it is the highest recorded for any single protected area in Southeast Asia. Indochina's largest population of rufous-necked hornbill lives here, birds heavy enough that their wingbeats are audible before they are visible. The upper montane forest holds the threatened beautiful nuthatch, and the wet eastern slopes shelter the Vietnamese crested argus and the short-tailed scimitar babbler. The mammal list is comparably strange: giant muntjac, Roosevelt's muntjac, Truong Son muntjac, the Indochinese warty pig, Heude's pig, the Annamite striped rabbit, Asian elephant and Indochinese tiger.
The Vietic peoples are indigenous to this area, and their languages - many of them critically endangered - carry a working knowledge of its ecology that no survey has matched. Saek speakers arrived from Vietnam roughly three centuries ago; Bru speakers came during the 1800s and 1900s and now form the majority. Then, in the 2000s, the plateau below changed shape. The Nam Theun 2 dam entered commercial operation in April 2010, flooding 450 square kilometres and requiring seventeen villages - about 6,300 people - to leave land their families had farmed for generations and start again in built settlements. Part of the bargain was that the project would fund the watershed above it, roughly a million US dollars a year, orders of magnitude more than Laos had ever spent on protected areas. The park was formally designated on 15 February 2019, and nominated to the IUCN Green List the following year. A wilderness is being paid for by the reservoir that displaced the people living at its edge. Both of those things are true, and neither cancels the other.
Nakai-Nam Theun National Park centres on 17.81N, 105.07E, straddling Khammouane and Bolikhamsai provinces in central Laos and covering about 4,270 sq km. The eastern boundary follows the crest of the Annamite Range along the Vietnamese frontier, rising to Phou Laoko at 2,286 m (7,500 ft) - plan terrain clearance accordingly. The single most conspicuous feature from the air is the Nam Theun 2 reservoir on the Nakai Plateau to the southwest: a 450 sq km sheet of water with a deeply irregular shoreline, unmistakable against otherwise unbroken forest. Best viewed from 10,000-14,000 ft AGL, high enough to read the ridge-and-valley grain of the Annamites. Nearest airports: Thakhek (VLTK) to the southwest, Nakhon Phanom, Thailand (VTUW), Vinh, Vietnam (VVVH) to the northeast, and Vientiane Wattay (VLVT). The Annamite crest generates persistent orographic cloud, and the eastern slopes are among the wettest ground in Indochina; expect the park to be under cloud through much of the May-October monsoon, with November to February giving the clearest conditions.