The Cordón Ilse Von Rentzell, located approximately 50km northwest of the Chaltén Massif, contains numerous beautiful and challenging summits, all of them believed to be unclimbed prior to our 2021 expedition. The range is named after German-born Ilse von Rentzell, who after emigrating with her family to Argentina, became a standout writer, painter, photographer, mountaineer, explorer, and plant geographer. She participated in several expeditions to the Andes, including a few adventurous weeks exploring the Lago O’Higgins/San Martín region of the Southern Patagonian Icefield in the summer of 1933. 

The 1933 expedition accessed the icefield from the east via Glaciar O’Higgins, which is flanked to the south by a then-unknown mountain range they called “GAEA,” after the Argentine Society of Geographical Studies, which sponsored the expedition. Further into the icefield, they observed and mapped for the first time a chain of peaks southeast of Cerro Pirámide; this is where Cerro Gorra Blanca (2,907m) and Cerro Falso Ilse (2,512m) are located; Camilo Rada and I climbed both in December 2008 (AAJ 2012).

To the north of Glaciar O’Higgins, they discovered yet another unknown range, an episode described by Ilse as follows: “We saw to the northwest, for the first time, in all its extension, a chain of mountains that still did not appear on the maps. Among this new mountain range, which presents the typical forms of pointy summits, runs the main glacier with a width of 40 or 45 kilometers.”

Later, in 1959, Hugo Corbella, Marcelo Costa, Jose Marticorena, and Pablo Schiffini made a notable expedition connecting Lago O’Higgins with Fiordo Eyre to the southwest and then crossing eastward back to Lago Viedma. During this exploration, they named the most well-defined summit of the range after Ilse to remember the first woman known to have set foot upon the icefields of Patagonia. Cerro Ilse Von Rentzell was coveted for decades, however, it remained unclimbed until April 9, 2021, when Camilo Rada and I reached the summit. We achieved this long-awaited ascent on the only good day of weather offered to us on our two-week expedition. In practice, it is difficult to define which of all the peaks along this range is Cerro Ilse Von Rentzell, so we went for the highest, which is approximately located where Corbella’s maps place it.

We achieved this long-awaited ascent on the only good day of weather offered to us during our two weeks at the Greve hut (having reached it by helicopter to do work as part of a maintenance crew). The hut is located at the very center of the icefield and to the southwest of Cerro Ilse Von Rentzel. Once we reached Ilse, we ascended the south face on skis until we reached the southeast ridge. There, we crossed the bergschrund and gained the last couple of hundred of meters using crampons on an icy 40° slope. The climb ended with a crux, 15m climb over a voluminous mushroom of rime ice: After 5m of vertical climbing, the angle gradually eased off until we stood atop a nice, flat, little summit. Our GPS gave us an altitude of 2,506m (48°43’50”S, 73°25’17”W), and the summit gifted us with expansive views of the icefield, surrounded by amazing mountains, so many of them unclimbed that our fingers run short to count them, in the very heart of the Southern Patagonian Icefield.

— Natalia Martínez, Argentina