Driving into the Llanganuco Valley I felt like I was in an IMAX theater. The smooth, black cliffs were not just steep, they seemed to curve overhead like the lower walls of a dome. I’ve never been to Yosemite Valley, but I imagine Llanganuco looks a lot like it, only narrower. Of course they should share some similarities; both were carved by glaciers!
Past the teal, landslide-dammed lakes Chinancocha and Orconcocha we drove, winding through polylepis forest and cow pasture until we reached Cebolla Pampa, or actually about 40 meters above Cebolla Pampa by way of a steep rocky path. This would prove a significant energy drain on the way back, when we had to lug our gear uphill at the end of a long day of work. Cebolla Pampa is a pleasant grassy flat cut into ribbons by a braided stream. The single plank crossing the nearest branch of the stream gave my balance a test several times but failed to bring me down.
Our main study site at Llanganuco is in the upper pampa about 400-500 meters above Cebolla Pampa. The hike there takes about an hour and a half to two hours, steepening steadily along the way. The trail, well marked by both cairns and erosion, begins with an unexpectedly tiring stretch that doesn’t angle uphill enough to warrant switchbacks but is just the right grade to leave you wondering why you’re tired. The trail soon crosses some sort of outwash fan, which judging from the size of returning plants looks to be only a few decades old. The thought came to my mind that perhaps Cebolla Pampa may not be the best campsite during the rainy season.
Up past a waterfall the switchbacks begin. Trekkers and cows frequent this part of the trail, which may lead to some delays. The first time I hiked down the trail, a cow charged another cow that was only a few feet from us. Climbing the headwall of the hanging valley, the two peaks of Huascaran tower over the valley below. A second series of sharp switchbacks completes the climb, spitting hikers out next to a small tarn just above the pampa. Our group maintains several piezometers in the upper pampa to learn about groundwater flow through the pampa. One of them was missing its data logger when we visited, which was disappointing, but we downloaded the rest of them and bailed out the wells so we could sample them the next day.
On our second day in Llanganuco, four of us set off from the upper pampa to the popular Laguna 69. A strange name for a lake? Yes. This formerly proglacial lake was named (or numbered) during an inventory of glacial lakes in the Cordillera Blanca. Getting there meant climbing yet another series of switchbacks up a steep slope. When we arrived on at the top of the ridge, the lake that awaited us displayed an incredible shade of blue. We took one good look before science called, then clambered down the dry outwash channel looking for the emergence of the stream and a place to sample the water.
We attracted some stares from trekkers 10 meters above on the hiking trail as we went about our work. Perhaps they thought a guy with shoulder length gloves struggling to filter water into a bottle as three other people crowded around was a strange sight to see in a gully high up in the Andes. Back at the lake, we witnessed a strange sight of our own: a cow was wandering along the lakeshore, posing for photos with opportunistic trekkers. We were far too serious to take a photo with the cow.
Glaciers line the tops of the cliffs and scree slopes that surround the lake. White rock, white ice, white clouds, and a very blue lake greeted us from the shore. Wind and a dash of frozen precipitation prevented us from staying at Laguna 69 for too long, but I will remember it as a beautiful lake and a top rate sampling location.
Down the switchbacks we trudged, punishing our knees for all of the good uphill work they’d been doing all day. Back at the pampa a sign pointed to the trail to Broggi Lake, our next stop. Shortly after the turnoff two of our group peeled off due to some discomfort at the elevation. Kelsey and I steeled ourselves for the rest of the journey, aware that we needed at least two people to complete the sampling. No more casualties allowed. As it turned out, the trail was the next casualty. If there is a man-made trail all the way to Broggi Lake, it doesn’t compete very well with cow trails, rocks, plants, etc. Having seen the lake from high up on the trail to Laguna 69, we were aware that whatever rut we were following was as likely to take us to the top of Chacraraju as it was to lead us to Broggi Lake. A rewarding cross country scramble ensued, culminating in reaching a high moraine ridge that gave us a view of Broggi Lake, and promised a difficult walk down to it over a field of surprisingly wobbly boulders.
Ankles thankfully intact, we reached the lake and were greeted by a wave of cold rain. Once three water samples from the lake outlet were bottled, we didn’t linger at the lake. Broggi Lake is just a memory of Broggi Glacier, which used to fill part of the valley. However, a warming climate is not kind to any glacier in the Cordillera Blanca whose accumulation area is well below the 5000 meter mark, and so Broggi Glacier is gone today. Broggi Glacier, named after Peruvian Jorge Broggi, is one of two glaciers in the Llanganuco Valley named after glaciologists. The Austrian, Hans Kinzl, whose glacier still flows down from the flanks of Huascaran several kilometers away, seems to have gotten the better half of the deal.
It had taken several hours, but by the time we left Broggi Lake we had water samples from two of the main water sources in the valley. We followed a ravine down to the pampa and made a beeline for Cebolla Pampa, where a late lunch, heavy equipment, and the promise of a long bus ride back to the comfort of Huaraz awaited.