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South America, Argentine-Chilean Patagonia, San Lorenzo Attempt from Chile

San Lorenzo Attempt from Chile. John Hauf, Tom Walter and I went in from the Chilean side, an interesting and varied six-day trip: by bus from Puerto Montt to Quellón, ferry to Puerto Chacabuco, bus to Coihaique, plane to Cochrane, horses to Arroyo San Lorenzo and finally by foot to the De Agostini Base Camp site at the edge of the forest. To drive in from the Argentine side is obviously simpler, but one needs the proper vehicle, access problems have been reported with the owners of the estancias, and the scenery on the Pacific side is better than the pampas. Coihaique has all the food and supplies an expedition might need at typical Patagonian prices. Cochrane, a very isolated village of 3000 people, has some food but it is expensive and there is no gas. At Base Camp we spent a few days scouting routes. One line that looks good is the north-northeast face at the head of the glacier that drains into the Río de Oro, a large alpine ice gully that goes straight to the summit. This gully would require cold weather as we watched much ice and rock falling down it on a warm afternoon. Instead we chose a line on the north face, directly above Base Camp. This face gets raked by ice avalanches from the ice cliffs at the top, but after watching it, we thought we saw a route that would keep us safe. We began on a beautiful hot day, March 3. The following day started clear and we set out from a bivouac at 2000 meters. After an hour of exposed climbing through séracs, we crossed the bergschrund and relaxed, continuing up on ice through small buttresses. What made the rest of the route fairly safe was that we were not in the larger gullies that receive everything falling from above. Our crux was a 40-meter frozen cascade, 70° to 90° steep and only a meter wide, which took us through a rotten cliff. It led to a snow ridge which went directly to the top cliffs, full of icicle-hung overhangs. Some zigzags through them got us to the summit ridge at four P.M. The weather was deteriorating fast, with a lenticular cloud over the summit and clouds sweeping in from the west. For that reason, we did not continue east to the very top. For a brief period, the view was spectacular, from San Valentín, across the valley of the Río Baker, south to the peaks of the Southern Icecap. We didn’t know how to get off the mountain quickly and without rappels, aware only that De Agostini’s first-ascent route was somewhere on the west side, and so we staggered through the wind for a while before finding an icefall that looked good. We raced down it under lowering clouds. We spent that night in rain and snow perched on rocks somewhere on the west side and returned to Base Camp the following day, March 5. Since the weather stayed unstable after this, we hiked in the neighboring valleys. The adjacent Cadena Cochrane has some very nice climbing and one can be active there even when upper San Lorenzo is engulfed in storm. Rock quality is disappointing on the north and west sides of San Lorenzo. Clearly, the big routes are on the east or northeast of the peak.

Timothy Rawson, National Outdoor Leadership School