On October 22, Alexis Trudel (Canada) and I left Cusco with Luis Crispin (Peru) and headed toward Mollepata. From there we headed to Soray Pampa by truck with Edwin Espinoza, who would join us for our climb. We hiked up to the base of Cerro Jatunjasa (5,350m, a.k.a. Incachiriasca) that same day and set up camp below the west face (ca 4,700m).
We left camp at 2 a.m. and made our way up scree to the base of the southwest ridge. The ridge looked easy from below, but we were in for a bit of a surprise. Higher up, as I surmounted a rock tower on the ridge I saw that it continued longer than expected and that we would have to do an exposed traverse on the south face below part of the ridge. We were able to simul-climb across the traverse, and above that we reached a small glacier atop a crest. An easy climb up the final part of the ridge brought us to the summit at 6:15 a.m. (350m, PD). We stayed on the summit for a while to admire Salcantay (6,279m) across the valley and then descended the north face on scree and easy rock.
From my research, Cerro Jatunjasa appears to have been climbed twice by the north face, in 1970 by a German expedition and then again by Conny Amelunxen and Karen Perry (AAJ 2004).
Nathan Heald, Peru