From October 29 to November 16, 2022, we—Rebeca Cáceres, Nadine Lehner, and Isidora “Isi” Llarena—put up a new route on Cerro Arenales (3,437m) and completed a 150km multisport traverse through the Northern Patagonian Icefield.

Cerro Arenales is the second-highest peak on the icefield and the fifth-highest in the Patagonian Andes. In 1958, a Chilean-Japanese expedition made the first two ascents via the south face. Eric Shipton’s legendary 1963 expedition made the third ascent via the same route. Since then, we believe this remote peak may have seen only one ascent (in 2006, by Franco Dellatorre, who afterward died in a crevasse fall near the mountain). Our goal was the north face, a route we had scouted during our 2021 expedition to the Colonia Glacier (AAJ 2022).

In late October, as a substantial weather window approached, we realized that high winds wouldn’t allow us to cross Lago Colonia by packraft in order to enter the icefield via Valle Colonia, as we’d done on two prior expeditions. Isi quickly proposed a Plan B: a 35km push through Valle Nef, only some of which would be terrible bushwhacking.

We set off right after a spring storm brought snow down into the valley, covering the just-emerging morels. We followed a horse track as far as we could, then scrambled through the lenga and coigüe forest to dazzling views of Arenales. During our approach through the forest, the wind was ripping, and nerves were high as we watched plumes of snow blow from our intended route on the north face.

Dropping to the Cachet Dos basin, we crossed the river by packraft and continued along the edge of the Colonia Glacier, now on familiar ground. Once we reached the edge of the icefield, we located a cache of skis, food, and gear that a helicopter had dropped for us a few days before. As predicted, the winds dropped just as we reached the icefield, and we knew our window had arrived.

To access Arenales, we crossed the wide Colonia Glacier, reaching a high plateau at 2,600m, where we built a camp with views out to the Pacific Ocean. On November 3, we made our first attempt. After six pitches of moderate ice (AI3), we were turned back by enormous open crevasses bisecting the route. We scouted a second possible route, and decided to make another attempt on November 4. This required stretching our remaining food and fuel to the limit. 

For our second and successful attetmpt, we dropped 150m from our plateau camp to gain a steep, northwest-facing ramp. We climbed 300m of moderate snow and ice up the ramp (WI2), then weaved through a section of crevasses and cauliflower ice formations to gain the less steep slopes above. After 3km more of snow travel, wrapping around toward the western aspect, we surmounted the summit snow and ice mushrooms without much difficulty. In all, our ascent took six hours (950m, WI2). The descent took another four hours, with soft snow and weak snow bridges, and one rappel.

Afterward, we spent several days hunkered down at base camp. Many stroopwafels later, a little break in the weather enticed us to bid goodbye to the nest we’d built (we even dug a snow cave that fit our packrafts as couches!) and start our traverse south. Packrafts were repurposed as sleds, and we crossed the Cordón Aysén on skis, following Shipton’s route. After two days (approximately 40km), we reached a helicopter-deposited cache of food and fuel, west of Cerro Bonete, our second climbing objective. The whole icefield is remote, but this area felt particularly wild and distant. Dark clouds perpetually lingered on the western horizon, reminding us of the proximity of the ocean. Many of the mountains we could see are unclimbed, as far as anyone knows.

After reaching our second planned base camp, we took a day to ski, do recon, and obtain a weather forecast. A storm with high winds was approaching with no foreseeable climbing window. After two days of waiting out weather, the sloppy, fast-melting snow conditions tipped the balance in favor of starting the long process of exiting the icefield and continuing our traverse. This became, in some ways, the most challenging leg of our expedition.

We ferried loads across the bare-ice glacier, exiting the icefield near Cerro El Mono, to the east of Glaciar Steffans. From there we descended, hiking into the coigüe forest and enjoying the sounds of birds and smell of plants with the acuity gained from living on the barren icecap. We paddled across a small lake as winds began to build and took refuge in a tiny clearing, the first sign of humans in days. We made it down to Río Huemules with only a small amount of bushwhacking and a new regard for temperate rainforest.

On our final day, we inflated our packrafts and finally set off downriver for one final, terrifying adventure resulting in scary swims, an improvised paddle, and deepened respect for the water. At last, we reached the fjords of the Pacific, where we crawled aboard the beautiful Paz Austral boat as though we had stepped into another universe. A few hours later, we were portaging our gear and skis through the boardwalks of Tortel to many a curious stare, feeling the mark left by our 19 days spent in and around the icefield. It is hard not to dream of returning.

— Rebeca Cáceres, Chile, Nadine Lehner, USA, and Isidora Llarena, Chile