Day three of four on our trek of the 46.5-mile Huemul Circuit in southwest Argentina, and for once there’s only scattered clouds in the Patagonian sky. Standing atop 3,269-foot Huemul Pass after 4 hours of climbing, I take a deep breath and steel myself for the descent, which drops more than 1,000 feet of scree in a mile. Shining down below, the Southern Patagonian Icefield sprawls to the horizon, where equally icy mountains raise 15,000-foot peaks to the sun.
I slide through my first step, then repeat. Slowly another landscape swings into view: At the base of the slope, drawing closer with each switchback, the Southern Icefield and Viedma Glacier spill into Viedma Lake. The lake, fifty miles long and nine across, soon draws most of my attention as the reflections of clouds skitter over its surface, broken only by the icebergs that crowd the glacier’s snout.
After roping up for a stretch of technical rock, my companions and I hear a sharp noise over the slither of moving scree: cracking ice. Hundreds of feet below, the icebergs are playing bumper cars, every collision throwing waves. There’s no time to linger, though. Tonight’s camp is at the edge of the lake, and we’ve still got a lot of descending to get there. But every step, slippery or sure-footed, brings me closer.