The Birthplace of the Pascua (Gary Hughes)

Before it reaches a fjord that links it with the Pacific Ocean, the Pascua River, in Chilean Patagonia, races for forty miles between the two largest ice-fields on Earth outside Antarctica and Greenland, cutting its path between two jagged mountain ranges. Born in South America's deepest lake, the Pascua is one of the fastest rivers in the world, embedded in a maze of canyons draining snow-capped peaks and glaciers.

It’s also one of the most secluded. Today there is only one road that will take you anywhere near the Pascua. Known unofficially as ‘Pinochet’s Road’ for the former Chilean dictator who pushed for its construction, the road is officially named after the military work camp at its end: O'Higgins.

• Part I 

The next day we all crossed the Quiroz. Halfway through our crossing, a yellow helicopter slowly approached and passed us from one direction, then turned around and buzzed past us again from the other direction. We didn’t pay much attention. We were too busy actually having a little fun riding the cable car—even though we were getting thoroughly soaked from the waist down because the cable sags and the car drags the rushing water for most of the trip across.

magellanic coigue and guaiteca cipres (Gary Hughes)

After everyone changed into dry socks and pants, we began walking toward the most unusual terrain of our expedition, a type of marshy area called mallín. Fortunately, the weather had been dry, and the mallín was crossable—just barely. It looks solid until you step into it. That’s when you realize that it’s just a very thick and very soggy carpet of peat moss and other vegetation floating in water. At regular intervals there are islands of magellanic coigue (nothofagus betuloides) and guaiteca cipres (pilgerodendron uviferum). We made a beeline for these tree islands at first, thinking that those trees had to be growing on solid ground. Instead we found the most bizarre forest we had ever seen, with very old but diminutive--some of them even bonsai-like--trees growing on huge humps of peat moss surrounded by water. We were finally able to cross the mallín only by walking around these miniature, floating old-growth forests!