mountain is the westernmost major peak of the Khumbu sub-section of the Mahalangur Himalaya 20 km west of Mount Everest. The mountain stands on the Tibet-Nepal border.
Just a few kilometres west of Cho Oyu is Nangpa La (5,716m/18,753 ft), a glaciated pass that serves as the main trading route between the Tibetans and the Khumbu's Sherpas. This pass separates the Khumbu and Rolwaling Himalayas. Due to its proximity to this pass and the generally moderate slopes of the standard northwest ridge route, Cho Oyu is considered the easiest 8,000 metre peak to climb. It is a popular objective for professionally guided parties.
Climbing historyCho Oyu was first attempted in 1952 by an expedition organised and financed by the Joint Himalayan Committee of Great Britain as preparation for an attempt on Mount Everest the following year. The expedition was led by Eric Shipton and included Edmund Hillary & Tom Bourdillon. A foray by Hillary and George Lowe was stopped due to technical difficulties and avalanche danger at an ice cliff above 6,650 m (21,820 ft) and a report of Chinese troops a short distance across the border influenced Shipton to retreat from the mountain rather than continue to attempt to summit.
The mountain was first climbed on October 19, 1954, via the north-west ridge by Herbert Tichy, Joseph Jöchler and Sherpa Pasang Dawa Lama of an Austrian expedition. Cho Oyu was the fifth 8000 metre peak to be climbed, after Annapurna in June 1950, Mount Everest in May 1953, Nanga Parbat in July 1953 and K2 in July 1954.
- 1952 First reconnaissance of north-west face by Edmund Hillary and party.
- 1954 First ascent by Austrians Joseph Jöchler and Herbert Tichy, and Pasang Dawa Lama (Nepal)
- 1958 Second ascent of the peak, by an Indian expedition. Sherpa Pasang Dawa Lama reached the peak for the second time. First death on Cho Oyu.
- 1959 Four members killed in an avalanche during a failed international women's expedition.
- 1964 Controversial third ascent by a German expedition as there is no proof of reaching the summit. Two mountaineers die of exhaustion in camp 4 at 7,600m (24,935 ft).
- 1978 Edi Koblmüller and Alois Furtner of Austria summit via the extremely difficult southeast face.
- 1983 Reinhold Messner succeeds on his fourth attempt, with Hans Kammerlander and Michael Dacher.
- 1985 On February 12, Maciej Berbeka and Maciej Pawlikowski make the first winter ascent (repeated three days later by Andrzej Heinrich and Jerzy Kukuczka).
- 1994 On May 13 Carlos Carsolio got the summit implementing a world record speed ascent from base camp, reached in 18 hours and 45 minutes.
- 1994 First solo ascent via the South West face by Yasushi Yamanoi.
- 2004 Second summit by double amputee (Mark Inglis)
- 2007 Second Indian ascent. Expedition led by Abhilekh Singh Virdi.
- 2011 Dutch climber Ronald Naar, known as the Netherlands most famous adventurer, dies after becoming unwell at 8000 metres (26000 feet).