Obispo and Fraile Grande, Altar Group, 1981. The Altar group consists of many peaks and pinnacles, which create the rim of a volcanic crater. Dave Jones and I climbed Obispo by its standard route, the south face. We bivouacked on the summit and then descended the long and difficult east ridge to the Obispo-Monja Grande col. From there we could descend to the glacier on the south side. This traverse took four days in late November 1981. In late December 1981 I returned with a Scot, Mike Orr and climbed the east ridge of the Fraile Grande, not a new route, and traversed the peak, descending the west ridge to a col from which we descended the glacier to the north.