Cho Oyu is the sixth-highest mountain in the world at 8,188 metres, on the Nepal–Tibet border about 20 km west of Everest. It is also the most frequently climbed of the 8,000-metre peaks after Everest, for a straightforward reason: its standard route from the north is the least technically demanding way to stand above 8,000 metres anywhere.
Why this one is the entry point
The north-west ridge route, approached from Tibet, is a long snow slope for most of its length. There is a rock band at around 7,000 metres that needs fixed rope, and the summit plateau is broad and can be confusing in poor visibility, but there is no sustained technical climbing and no equivalent of Makalu's final rock pitches or K2's Bottleneck.
Two further advantages compound it. The base camp on the Tibetan side is reachable by vehicle, which removes the long walk-in that other 8,000ers demand and makes logistics dramatically cheaper. And the mountain's objective dangers — serac fall, crevasses, avalanche-prone slopes — while real, are more manageable than on many of its neighbours.
The result is that Cho Oyu functions as the standard proving ground. Climbers use it to establish whether they can operate above 8,000 metres before committing to Everest, and guiding companies use a successful Cho Oyu ascent as a qualification for accepting clients on harder objectives.
That reputation carries a risk worth naming: an easier route at 8,188 metres is still 8,188 metres. Altitude sickness, cerebral and pulmonary oedema, frostbite and storms do not care that the ground underfoot is gentle, and people have died on Cho Oyu doing nothing technically difficult at all.
The turquoise goddess
The name is Tibetan, generally translated as turquoise goddess, and the usual explanation is the colour the mountain takes on in certain light — a bluish cast on the snow that reads as turquoise from the Tibetan plateau side. Turquoise is a stone of considerable significance in Tibetan culture, associated with protection and with the sky.
The mountain sits immediately north of the Nangpa La, a pass at about 5,716 metres that has been the main trading route between the Khumbu in Nepal and Tingri in Tibet for centuries. Sherpa communities in the Khumbu trace their origin to migration over this pass from eastern Tibet several hundred years ago — the word Sherpa itself means eastern people.
The Nangpa La has also been a refugee route, and it was the site of a widely reported shooting in 2006 when Chinese border guards fired on a group of Tibetans attempting to cross, killing a teenage nun; the incident was witnessed and filmed by climbers at Cho Oyu's base camp.
How much easier is easier
It is worth being precise about what Cho Oyu's reputation means. The standard route is graded well below the technical difficulty of Makalu's summit ridge or K2's Bottleneck, and it involves no sustained steep ground.
But summit day still means eight to twelve hours of movement above 7,500 metres, in temperatures that can fall below minus 30 degrees Celsius with wind on top of that, breathing air with roughly a third of the oxygen available at sea level. Frostbite is common. Pulmonary and cerebral oedema occur on Cho Oyu as they do anywhere at that altitude, and both can kill within hours if a descent is not started immediately.
The mountain is easier than its neighbours in the specific sense that the climbing is simpler. It is not easy.
A first ascent that broke the rules of the era
Cho Oyu was first climbed on 19 October 1954 by Herbert Tichy, Josef Jöchler and Pasang Dawa Lama, and the manner of it was as significant as the fact.
The 1950s were the age of the siege expedition: large national teams, many tons of equipment, long chains of stocked camps, and hundreds of porters. Tichy's party consisted of three climbers and a small number of Sherpas, travelling light and cheaply, and they summited without supplementary oxygen.
They also did it late in the year, in October, when most expeditions had gone home, and Tichy climbed with hands badly frostbitten from an earlier storm in which he had held down a tent. The ascent is often cited as an early demonstration that small teams could succeed on the highest mountains — the argument that Hermann Buhl, Messner and others would push much further over the following decades.
The problem of what counts as the summit
Cho Oyu's top is not a point but a broad, gently domed plateau, and in cloud it can be genuinely difficult to establish where the highest ground is. This has generated a persistent controversy.
Analyses of summit photographs and GPS records have suggested that a significant number of parties over the years stopped on the plateau short of the true high point, particularly in poor visibility, and some prominent claimed ascents have been questioned on those grounds. Because Cho Oyu is so widely used as an Everest qualifier and as a tick on the fourteen-8000ers list, the stakes attached to the claim are higher than the terrain would suggest.
The mountain is not unique in this — several 8,000ers have contested summit definitions — but its flat top and heavy traffic make it the most frequently discussed case.
The mountain from the Gokyo side
For anyone not climbing it, the best ground-level view of Cho Oyu is from the Gokyo valley in the Khumbu, west of the main Everest trekking route. The valley holds a chain of glacial lakes at around 4,700 to 5,000 metres, dammed by moraine from the Ngozumpa glacier — the longest glacier in Nepal.
From the summit of Gokyo Ri, a walk-up peak above the lakes, the panorama takes in four 8,000-metre mountains at once: Everest, Lhotse, Makalu and Cho Oyu. It is one of very few places on Earth where that is possible, and it is reachable by a fit walker without technical equipment.
The Ngozumpa glacier below is heavily debris-covered and studded with supraglacial ponds, and it has been thinning measurably. Those ponds coalescing into larger lakes is the mechanism by which outburst flood risk develops, and the Gokyo system is among the more closely watched in the Khumbu.
Where it sits among the fourteen
Ranked against the other 8,000-metre peaks, Cho Oyu is an outlier in a useful direction:
- Ascents: second only to Everest in total summits, and by a wide margin ahead of most of the rest.
- Fatality rate: among the lowest of the fourteen — a small fraction of Annapurna's, which is the most dangerous by a considerable distance.
- Cost and logistics: the cheapest of the 8,000ers to attempt in most years, because of the drivable base camp.
- Technical grade: the lowest, which is precisely why the other figures look as they do.
Access has fluctuated with Chinese permit policy for the Tibetan side, and in years when Tibet has been closed to foreign expeditions the Nepali south-west face — a far more serious proposition — has been the only alternative, with a corresponding collapse in ascent numbers.
The other side of the mountain
Everything that makes Cho Oyu approachable applies to the north-west ridge from Tibet. The Nepali side is a different mountain entirely.
The south-west face is a steep, complex wall of roughly 2,000 metres, and it has been the setting for several landmark ascents — including a 1978 Austrian route and, in 1994, a fast alpine-style ascent by Voytek Kurtyka, Erhard Loretan and Jean Troillet that is still cited as a model of the style. Very few parties attempt it, and the contrast with the crowds on the northern slope in a normal season is total.
This matters practically because access to Tibet is a matter of Chinese permit policy, which has closed and reopened unpredictably. In years when the northern approach is unavailable, Cho Oyu effectively drops off the commercial map, since the alternative is a technical face rather than a snow slope — and the peak's ascent statistics show sharp discontinuities as a result.
Records set on its slopes
Because Cho Oyu combines genuine 8,000-metre altitude with manageable terrain, it has become the place where a number of firsts and records were established.
It saw early high-altitude ski and snowboard descents, including Hans Kammerlander's ski descent in 1996. It has been the site of several speed ascents. And it has repeatedly served as the mountain on which climbers pursuing all fourteen 8,000ers begin, or on which they test themselves after injury.
Its role as an Everest qualifier has also made it a commercial hinge: when it is open, guiding companies use it to filter clients, and when it is not, that filtering either moves to Manaslu or is quietly dropped — which has consequences for who ends up high on Everest the following spring.
What it is like up there
The Tibetan approach crosses high, dry, wind-scoured plateau country, and the contrast with the Nepali side of the range is stark: the Himalaya wring the monsoon out on their southern flank, so the northern approach is a cold desert while the valleys 30 km south are forested.
From the summit plateau, in clear weather, Everest stands up to the east with Lhotse and Nuptse beside it, and the view west runs along the chain toward Shishapangma. Below to the south, the Gokyo lakes sit in their valley — a trekking destination in the Khumbu that offers one of the better ground-level views of Cho Oyu, from the summit of Gokyo Ri. For the geological story behind the whole chain, see our Himalaya guide.
