In November of 2024, Caltopo Adventure Grant Recipient Nadine Lehner and two friends set out to attempt a traverse of the vast Northern Icefield in Patagonia. For this trip they brought along skis, packrafts and mountaineering equipment (a feat to carry in and of itself). Below is Nadine’s report of this journey, and the use CalTopo in both planning and navigation. Enjoy!
Ask what makes Patagonia legendary as a mountaineering destination, and you’ll hear a lot about the bad weather. Gale force winds, storms that last for weeks, rime ice coating exposed rock…all true! But an overlooked challenge to exploring the mountains of the Southern Cone has been the lack of accurate, detailed maps.
In Chile, some of the most useful topographical maps come from the Instituto Geographico Militar (IGM), generally at a 1:50,000 scale with 50m contour intervals. Even to the present, hand-drawn sketches from early explorers such as Alberto de Agostini, Hans Steffen and Gino Buscaini offer useful insights for would-be mountaineers looking to climb new peaks or establish new routes. One of our expedition-members, Marcelo Mascareño, has spent years collecting maps and drawings from early explorers, looking to gain insights about the exploration of remote parts of Patagonia.
Historic Map of Patagonia
After years of exploring Patagonia with minimal (if any) useful maps, we found CalTopo’s range of imagery and data a game-changer as we planned, re-planned, and undertook a recent expedition to the Northern Patagonian Icefield in Chile’s Aysén Region.
The first seed of an idea for this expedition came in December 2021, when Rebeca Caceres and I (Nadine Lehner) climbed Monte San Valentin, Patagonia’s highest peak, during a phenomenal weather window that allowed us to see down across almost the entire icefield, stretching out to the fjords of the Pacific Ocean. As we made the long ski descent from the summit, we batted around the idea of skiing straight across the icefield and ending in the ocean. From up high on a perfect bluebird day, the traverse seemed like an obvious and inevitable idea.
Since then, other climbs and expeditions took priority, such as establishing a new route on Cerro Arenales (which Rebeca and I did, with teammate Isidora Llarena, in November 2022), and attempting an unclimbed peak next to Cerro Meliquina (a trip I undertook in November 2023, with support from CalTopo’s Adventure Grant). However, in March 2024, Rebeca resurfaced the idea of an icefield traverse. At the time, she was recovering from a brain illness that forced her to bow out of a climbing expedition on the icefield. Returning to this special, austerely spectacular place would represent a milestone in her recovery. Marcelo Mascareño, another long-time Chilean NOLS instructor, signed on, as did I.
We blocked our calendars for three weeks in November 2024 and found moments between field work review spreadsheets of food and gear and logistics. We applied for permits and for funding (thank you, again, CalTopo, for supporting this expedition!). Most of all, we visualized ourselves THERE: skiing across a dazzling white landscape, climbing remote peaks along the way.
Planning Map in 3D on CalTopo
We envisioned many potential objectives and routes. The CalTopo map that grounded most of our planning started to look like a Jackson Pollack painting as we studied various access and egress routes from the icefield, as well as multiple new routes on three peaks. I took an excellent online course with Alaskan explorer Luc Mehl (“Start and End at Home”), which helped us gather information on weather trends, satellite imagery, and new tools for receiving forecasts in the view.
Master map with Satellite imagery on the Mobile App.
CalTopo’s 3D features proved especially useful to allow us to visualize a potential new route on San Valentin, on the opposite face from where Rebeca and I had climbed in 2021. We could compare the 3D map to aerial photographs that I found through some deep Instagram stalking of an outdoor influencer on a scenic flight, which gave us a more detailed look at which parts of the route would present the most difficulty.
Monte San Valentin
As our dates approached, so did the low-pressure system. The glorious weather window we had envisioned was nowhere in sight, but previous icefield expeditions had taught us that you can’t be too choosy with the window. Sometimes the weather is better than forecasted, and sometimes you can fit more into a short window of decent weather than you expected.
Ready to go!
So as the days of November passed by, we decided to pare down our initial plan and go for it. At this point, we had studied three potential entrance routes to the icefield: Lago Leones, Las Gualas, and Glacier Grosse.
Studying our master trip-planning map helped us understand the length, difficulty, and hazards of each option. Lago Leones was the longest entrance and required gaining almost all the elevation needed for the traverse (~2,000m) over the first two days (See Caltopo’s Line Profile feature below). Las Gualas was the most gradual ascent, remaining at lower elevation for more distance. Glacier Grosse offered the shortest approach to San Valentin, but also the greatest technical difficulty and avalanche hazard. Knowing that substantial snow had fallen recently, paired with days of very high winds, we flagged the Grosse route as too high risk, opting not to continue studying this option.
Leones approach profile in Caltopo
Gross approach profile in CalTopo
From there, we saw three options: enter and exit via the same route (either Leones or Gualas) and attempt the new route on San Valentin, traverse from east to west (Leones to Gualas), or west to east (Gualas to Leones). We saw merits in each option: attempting the new route seemed an exciting chance to move through steeper, more technical terrain, while each direction of the traverse presented pluses and minuses. Studying the weather window more led us to abandon the peak attempt (for now! We continue to scheme!), as we needed more clear, low-wind days for that.
From there, the west-to-east vs. east-to-west debate continued! Major pro of starting in the west: prevailing winds at your back! Major pro of starting in the east: steeper ascent, followed by long (40+km) gradual ski descent. In the end, much as we debated, it turned out to be a logistical footnote (the boatman who could take us into Gualas only has limited availability) that forced our decision. Off to Leones we’d go!
We timed our departure to enter just before the weather was forecasted to improve, as we knew we could hike at least the first 10km to Lago Leones in the rain. We crossed Lago Leones in high winds, with the boat barely able to leave the shore, but a huemul on the far shore seemed a good omen. We schlepped upward through spectacular forests and played our first game of Yahtzee with Rebe’s absurdly tiny dice. Switching to skis at last, we made our way toward the edge of the icefield. With the wind periodically blowing us over, we checked the weather one last time before committing.
Wall of clouds hanging above the pass.
At this point, we were about five hours from the literal high point of the trip, Paso Tararua, which guards the eastern access to the icefield. Between Cerro Mocho and Cerro Cristal, this 2,150m pass received high winds blowing unblocked from the Pacific. Hanging above the pass was a wall of ominous grey clouds, which reminded us of a moving walkway overhead, blowing fast but not advancing.
We needed lower winds to make the exposed move over the pass–but we also could not expect to find much protection on the other side. Even though we’d be slowly losing elevation, the vast exposure of the “pampa” of the icefield allows winds to build.
Incredible scenery on the Icefield.
As we re-checked the forecast, we saw that while the winds were predicted to drop that night, they were now predicted to build again the following afternoon. That gave us enough time to cross the pass in low wind, but not enough to traverse the icefield. We found a nook out of the wind to make a hot drink and re-study the map and weather models to think over our decision.
We have all weathered storms on the icefield. Holding up tent poles as they bow in 100km+ winds and digging a snow cave is a memorable experience. We knew we could ride out some amount of high winds, but the forecast didn’t show a clear promise of when we’d be able to move again. We’d planned and packed for a more fast-moving trip, and didn’t have the resources to wait in the middle of the icefield for very long. Plus, the forecast showed a more-promising weather window coming in a week.
Skiing down the glacier.
It’s tempting to look back and congratulate ourselves for making “good decisions,” but the absence of the counterfactual makes accessing your decision-making close to impossible. Would the winds have been as high as predicted? How fast could we have moved? Where’s the line between discomfort and risk?
We THINK we made the right decision: to ski and explore in that zone, then return to town in hopes of a better window to come. But we felt some regrets when the promised “good” weather never materialized.
We had our bags packed, plans made for a second attempt, this time from the west side. After studying our previous attempt, we thought that having the wind at our backs could offer a significant advantage. Now knowing the Leones route well would help us toward the end of the trip.
However, as we were about to get in the car, we learned that the boat in the fjords could not depart due to high winds. We waited a day for the weather to improve, but by that point, the promise of a good weather window had changed. The forecast showed rain almost every day, with very low visibility. We debated HOW bad could the weather be for us to push forward, but ultimately decided to scrap the plans. Rebeca’s allotted vacation window was coming to an end, and skiing in a downpour in a whiteout through complex terrain did not appeal (although, yes, the satellite imagery does do a great job of hinting at crevasses, we needed some visibility to move with lower risk).
Complex terrain: visibility is a requirement.
The more we reflected and talked over our days in the mountains, the more we realized we learned from this adventure: in making plans and adjusting plans, and in coming to peace with the decisions made along the way.
I also realized that having doubts, and a tinge of regret, is also a blessing— a reminder that we really WANT to do the thing. Continuing to second-guess ourselves, although frustrating, is a tool for studying decision-making. As Rebeca put it, it’s been a journey inwards, playing with our hearts and encouraging us to continue dreaming
… and we’re excited to use newly learned mapping tools to make these dreams more precise and achievable! Thanks again to CalTopo for the support, and for providing such high-quality planning tools that make complex expeditions like this far more achievable than in the days of paper sketches and 50m contour intervals!
Nadine and her partners used both free and Pro level features to plan and execute their traverse attempt. Some Pro level features include 3D Mapping, Live Satellite Imagery, and importing Custom Map Sheets. To upgrade to pro for these and other features, go to Caltopo.com/join .
