Cordon de los Pioneros, various ascents. In December our group climbed previously virgin summits in this range, south of Pico Bicentenario. None currently has a name, and all were technically easy. Italians claimed to have climbed a summit here, but no traces of a previous ascent were found. After acclimatizing in the Valle de Chaschuil, above Fiambala, we used 4WD to reach a base camp at 4,650m in the Quebrada de los Burritos Muertos. From the 2nd to the 4th, we further acclimatized and established a camp at 5,276m (27°58'21.3" S, 68°47'06.5" W), west of the Cordon. On the 5th Dante Alegria, Mike Freeman, Tim Pearce, Tom Rankin, Marcus Risdell, and I climbed Peak 6,152m (map height, 6,193m GPS, 27°57'06.3" S, 68°45'16.5" W) from the west. There are two summits of more or less identical height, situated either side of a shallow crater with no lake. No cairns were found, but we built one on the southeast summit.
On the 6th Rankin and I climbed Peak 6,243m (GPS, 27°56'23.7" S, 68°44'50.8" W) immediately to the northeast. No trace of a previous ascent was found, and we left a cairn between two lava pinnacles 30m apart; either could be the highest point. The same day Alegria and Pearce climbed Peak ca 6,150m (Google Earth estimate) by the rocky southwest face. It lies south of Peak 6,152m. They were joined by Freeman for an ascent of a smaller peak, of ca 6,000m, to the southwest.
On the 9th two previously climbed peaks in the Sierra del Veladero, west of base camp, were ascended. Rankin and I climbed Baboso (6,070m map, first ascent probably 2000), scrambling along the narrow northeast ridge, over the northeast summit (a minor point probably unclimbed prior to our visit). Our GPS read 6,070m on the northeast summit and close to 6,080m on the main summit. The same day Alegria and Risdell climbed Reclus (6,335m map, first ascent pre-Colombian).
When I got home and researched my notes from an expedition made to Bonete in 1997,I discovered I had climbed the summit marked as 6,144m on the map, immediately east of the ca 6,000m peak climbed by Alegria, Freeman, and Pearce. I climbed this from a camp due east, starting with a client who waited at 5,800m, on the east slope, after we had crossed Point 5,850m.
John Biggar, Alpine Club, U.K.