Follow the directions in the Getting There section to reach Warm Springs Saddle. Take trail 344 to the left following the sign to Rainbow Lake. Rainbow Lake is a mile down the trail and is where the route starts.
Hike around the north shore of the lake and proceed up the basin to the north. Soon the drainage will curve to the west and start to rise. Hiking up the bottom is a bit monotonous due to the jumbled steep rocks covered with a dense tangle of brush and small trees. There are also many small streams cascading down to negotiate. There is no best way to go, but keeping to the right or north edge of the bottom avoids most of the worst brush, but there will be some granite to scramble.
Eventually the brush will diminish below the steep headwall. This ring of broken cliffs can be scaled at several places. An obvious path appears to be up the center, but that means more of a climb and does not position you as well for the summit ascent. There are several small runs in the rocks that go up and to the right of the center. Most are choked with small subalpine fir and prickly currant, but some have less brush. Take one of those. Once on top continue up and to the right across the bare rock talus toward the base of the final summit rise.
Between the shear rock of the south ridge on the left and the steep outcrops of the northeast ridge on the right there is an open stand of mostly dead or dieing whitebark pine. Proceed up into these keeping a southeast aspect. Soon 50-60 foot cliffs form abrupt outcrops ahead. Head toward these, but keep on the left as they approach. The path is highlighted by a stand of a few large robust whitebark pine that really stand out among the declining forest. Pass through these and into the more open, skeletal trees above. There is no definite way to go from here to the top, but keeping against the rugged outcrops on the right provides better rock and footing as the summit gets close.
Good hiking boots are all that is required. An ice axe and crampons are recommended for a spring or early summer attempt when snow will be present.
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