The Hornbein Couloir is a notable narrow and steep couloir high to the west on the north face of Mount Everest in Tibet, that extends from about 8000 m to 8500 m elevation, 350 metres below the summit. For the first 400 m vertical, the couloir inclines at about 47 degrees, and the last 100 m is narrower and steeper with about a 60 degree average incline.
To the east on the north face with less angle is the much larger Norton Couloir.
Origin of the name
The couloir was named after a member of the 1963 U.S.A. Everest Expedition, Thomas Hornbein, who was on the first ascent.
1963-05-22: Tom Hornbein and his partner, Willi Unsoeld, were with the 1963 U.S.A. expedition who were attempting to reach the Everest summit from the Nepalese southern side by two routes. The majority of expedition members used the same route climbed ten years earlier by Tenzing Norgay and Edmund Hillary. This entailed negotiating the Western Cwm and the flank of Lhotse to the South Col, then up the southeast ridge to the peak.
Hornbein and Unsoeld, however, took a more challenging, different and unknown route up the west ridge from Camp 2 in the Western Cwm, traversing over the north face to ascend the steep and narrow couloir. After summiting, they descended the southeast ridge, bivouacking high up.
Subsequent Successful Ascents
Since the initial ascent, there have only been another nine summiters with five expeditions through the Hornbein Couloir, the last one in 1991.
1986-05-20: Canadians Sharon Wood and Dwayne Congdon climbed a new west shoulder route from the Rongbuk Glacier and continued on to the summit via the Hornbein Couloir. She became the first North American woman to summit Everest.
1986-08-30: Swiss Erhard Loretan and Jean Troillet, unprecedented and unrepeated, climbed the north face in a single alpine style push without oxygen, ropes, or tents in 37 hours, and glissaded down in under 5 hours. They climbed mostly at night and carried no backpacks above 8000 m, a style that that became known as "night naked".
- Thomas Hornbein: Everest - The West Ridge. The Mountaineers Books, 1998, ISBN 0898866162, 9780898866162