Take the road N from the town of Sajama less than a mile to a small building on the right side of the road. The trail heads N parallel to the road accross flat ground, ascending a S facing hill a short distance before turning right (E) to follow the drainage. In 2 - 3 hrs there is camping on open ground near the stream. Clear water from a spring flows into the S side of the stream near the head of the drainage. A stone shelter is nearby. Stay to the N side of the stream when heading out to high camp to avoid quicksand like mud in the center of the basin. Ascend scree NE, maybe snow near top, over the low ridge and into the next basin to the N. Head NE accross the basin and N up and accross the steep slope on the far side to gain the lower NW Ridge. Ascend the moderate angle slope on the N side of the ridge to camp on snow platforms at the top of the rock outcrop on the right, which up to this point had blocked the view to the S.
Follow low angle slopes up the ridgeline until steep rock above on the left gives way to a broad snow slope leading up and left to the ridge crest. This slope is moderately steep and, given the substantial exposure, some may want to protect it with pickets. After a short airy traverse on the ridge crest, the route goes straight up low angle glacier to the summit, with nothing to stop you but weather and altitude.
Basic glacier climbing gear is required, including ice axe and crampons. We did the route very early in the season and encountered no cravasses, so I suppose it could be soloed or skied by appropriately skilled individuals. We took a rope and, using a running belay, placed a couple of pickets on the steep slope leading to the ridge crest above high camp. Wind and cold are primary concerns, making a bombproof tent and warm lightweight clothing a must.
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