Take a 4x4 from Sajama village ($80) or hire mules (75 Bs) for the 7 hr walk in across the flat, soft, and sandy altiplano. Make sure the mule driver knows where the camp is. The route bascially goes a bit south of Parinacota then winds back to the saddle of the two peaks at the end.
Reach the base of the peak and follow the well defined rocky rib towards the ridge, about 4 hrs. Upon reaching the snow go either directly up towards the crater or traverse to the ridge and then up that to the crater edge. Traverse along the crater ridge past one false summit to the true summit on the north side.
When enough snow exists you can climb the snow gully to the right of the the rib. It is more direct to the ridge.
Crampons, long axe, trekking poles.
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