Being the second highest peak in the Austral Patagonian Andes, San Lorenzo lies certainly in a privileged location. Between the north and south patagonian ice caps, with a relatively easy access, this frontier peak (its main summit lies in the Chile/Argentina border) will grant stunning views to whoever ventures into its glaciers and passes. From Mount San Valentín to Fitzroy, the dry argentinian pampa and the exuberant Chilean Patagonia, full of rivers, glaciers and rugged peaks. All this and more conforms the scenario where we find this colossal massif.
Its severe weather has allowed Monte San Lorenzo (or Monte Cochrane, oficial Chilean name) to withstand relatively few absolute ascents since in 1943 the Italian Salesian priest, Alberto María de Agostini reached its main summit the 17 of December, together with Bariloche guides Hemmi and Schmoll. As a matter of fact, until 1995 the peak had been climbed only ten times.
De Agostini´s ascent was the culmination of an exploration process which led him during three consecutive years (1940 - 1942) to explore the different faces of San Lorenzo, until he was finally able to design a feasible route. San Lorenzo´s complicated form well explains this need for previous exploring. Depending on the observation point, it will seem an entirely different mountain. It is only studying a topographic map or looking at an aerial picture that one can fully grasp the strange geography of this singular peak.
Twelve years passed before San Lorenzo was climbed a second time by four Argentines from the CABA (Buenos Aires Alpine Club), again by the Agostini route. Besides Agostini´s route, there is a route to the main summit which goes up the East Ridge, the most elegant line of ascent to the summit. This route remained uncompleted until 1986, when South Africans Paul Fatti, Erwin Muller, Russel Dodding and Hans Peter Bokker climbed the whole line to the summit after having failed in several previous attempts.
Recommended reading: "Patagonian Andes" (Alberto M. de Agostini) and "Patagonia" (Gino Buscaini and Silvia Metzeltin).