The approach is a fairly short ( 3 miles ? ) hike from South lake via the Bishop Pass trail, the Treasure Lakes trail and cross counrty hiking up slabs and scree to campsites at the base on Mt. Gilbert. This can also be easily done as a day trip from South Lake.
The 900' 50 - 65 degree couloir is obvious. The bershrund if present is usually easily crossed. Rock belays on the side of the couloir are possible. At the top of the couloir, turn left and follow a corner and slabs to the right of the corner to the summit. This is an excellent ice climb.
A note on the rating - the old Roper guide rated this climb III, 5.6 / AI2 or WI3, as does the current Secor guide book. The Sierra Classics guide ( Moynier & Fiddler ) calls it class 4 - 5. This is probably a more realistic rating, but there are several ways to finish the last pitch, so I'll leave the original rating. If there is fresh snow on the final slabs, you better be able to lead 5.6!
Descend the class 2 Southeast slope route to Treasure Col ( see the High Sierra guide book by R. J. Secor ) or, if you're camped below the North Face, I've used this descent - rappel or downclimb from the summit back to the top of the couloir. Continue descending to the west down a rock chute ( rappels ) until one is able to climb through the notch west of Mt. Gilbert and back to the cirque north of the peak.
Ice axe and north wall hammer, crampons, rope and a light rack, a few screws.
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