The Cordón del Mesón, south of Lago Viedma and El Chaltén in Parque Nacional Los Glaciares, and to the east of Cerro Moyano and Cerro Norte, has seen very little attention over the decades. Three of the eight or more summits in this group have been reached, but the surrounding peaks remain incognito. After a good bit of scouring Google Earth and other sources, a plan sprouted.

On November 8, Maxi Abasto and I left El Chaltén with the idea of finding something new to climb. We drove along Río Cóndor toward Puesto Colorado as far as the mud allowed and camped at the truck for the night.

The following day, we walked west, deeper into the valley, traversing many boulderfields and cow swamps. After crossing Río Cóndor Chico, we headed south; the traces of cows vanished, and we found ourselves in an untouched lenga and ñire forest. After some hours of being effectively lost, we made our way west up an unnamed side valley that we hoped would lead to the south ridge of Cerro Mesón (2,458m). Eventually we realized our maps had marked Mesón incorrectly.

We now found ourselves in a valley with little in the way of climbable terrain. Luckily, Cerro Brechón (2,418m, 49°48.49’S, 73°00’W), on the southern edge of this valley, appeared to offer some easier ridge and glacial terrain that led to what we assumed was a summit of some sort. We camped along a glacial lake and started our climb the following morning.

Glacial benches and easy snow led us to a couloir that would give access to a hanging snowfield and the northeast ridge. A short bit of blocky scrambling then brought us to the summit, where we could see from Paine Grande in the south to San Lorenzo in the north. Our route, Filo de Huemul, gained more than 1,500 meters from the valley floor. We descended the line of ascent with downclimbing and a handful of short rappels.

This area offers many more unclimbed peaks and attractive alpine objectives, particularly of the mixed variety.

—Kiff Alcocer, Argentina

UNCLIMBED PEAK ATTEMPT: A few weeks after the ascent described above, Kiff Alcocer returned to the same area south of Lago Viedma with Jordon Griffler and Bennett Wolfe. At the river fork where they had previously turned south, they instead took the northern valley, heading past a lake toward the most impressive still-unclimbed peak in the range—a massive mountain with a striking hanging glacier and well over 1,000 meters of vertical relief (summit: -49.736978°, -73.004082°). They climbed a number of pitches along the north ridge and continued onto the east face, but the rock proved quite loose. Higher up the face, Alcocer was struck on the shoulder by rockfall, forcing them to retreat.

—Rolando Garibotti