Type: Trad, Ice, Snow, Alpine, 1600 ft, 8 pitches, Grade III
FA: John D. Mendenhall - 1931
Page Views: 2,395 total · 37/month
Shared By: Preston Rhea on Nov 4, 2013
Admins: Chris Owen, Lurker, M. Morley, Adam Stackhouse, Salamanizer suchoski, Justin Johnsen, Vicki Schwantes

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The Northwest Couloir goes by many names among climbers: the Mendenhall Couloir, the Y Couloir, and most famously the Death Couloir. Under the first ascent conditions there was supposedly a snow apron allowing easier access to the couloir proper. When John Mendenhall climbed this in 1931, he called it third class. Since then, the route is considered "in" when the couloir is connected to the snow apron via a WI3-4 waterfall.

The first pitch is this waterfall and is the crux of the route. Once established in the couloir, easy to moderate snow climbing leads up to the fork or "Y". Take the left branch towards the summit. Part of the way up the branch a short WI3 pitch may be encountered.

The route is a funnel of debris and has serious problems with rockfall. It is only safe when full from the very bottom to the very top with snow and some may add only when climbed before the sun hits it in the morning. Regardless, do not spend longer than you have to on route.


Approach the north face of Mount Morrison via the hanging valley below. The couloir to the right of the north buttress is obvious.

To descend, walk off via the eastern slopes. Descending the Northwest Couloir is not recommended due to the potential for rockfall.


Ice screws and a small alpine rock rack. Snow pickets or stakes may be useful as well. The rock on both sides of the couloir is loose, but a creative leader can find protection.
Preston Rhea
Mammoth Lakes
  WI3-4 Mod. Snow
Preston Rhea   Mammoth Lakes
  WI3-4 Mod. Snow
When I saw this route form up in the last week of May 2011, I went up to climb it but found it to be avalanching spindrift every thirty seconds or so. I went back during the second week of June 2011 and successfully climbed it. I saw only occasional evidence of rockfall and did not experience rockfall at all during the climb. I was only on route for about an hour and a half from start to finish and all before sunrise. Because of the stories and what I saw when I first attempted it, I would recommend not spending any more time in the couloir than you have to.

Also, the actual formation only lasted from the very end of May until maybe the 16th of June in 2011. I climbed it on the 13th and found it to be melting fast. Nov 4, 2013