REACH FOR THE SKY

The route from Chile's Atacama Desert to Bolivia's Salar de Uyuni salt flat is one of the most spectacular-and inhospitable on the planet. Mark Johanson embarks on a new expedition that retraces ancient caravan routes and makes this extraordinary journey more accessible than ever before.

- Mark Johanson

I CAUGHT MY BREATH as the flamingos suddenly set flight over Laguna Colorada, a rust-colored salt lake in southern Bolivia. All afternoon the rare birds had been standing, rump-up, head down, busy eating the algae that turns their bodies pink. Then, disturbed by a grazing vicuña, the flamboyance, as a flock of flamingos is known, took off.

Hundreds, if not thousands, of the birds soared, low and heavy, over the water, which stretched out in front of me like a pool of molten brick, and careened onward toward distant, snow-speckled hills. Up to 40,000 James's flamingos-roughly half of the species' entire population can gather around this shallow salt lake on Bolivia's Altiplano, also called the Andean Plateau.

Other than my guide, David Torres, I was the only human around to witness this extraordinary spectacle. Walking this part of the Andean Plateau with Torres felt like exploring the surface of some foreign planet where the ground is white and the water is red. As I stood 14,000 feet above sea level, feeling the heat of aggressive sunbeams on my cheeks, I felt so close to the sky it was like I'd left Earth entirely.

In reality, I was beginning a weeklong journey along a portion of the Qhapaq Nan, a road system of the ancient Incan Empire that extends more than 18,600 miles across six countries. Torres was to usher me on a travesía, the Spanish word for a long crossing or journey through a wide expanse of terrain, that would cover 300 miles of the route. Caravans used to follow this path through Bolivia and Chile, their llamas carrying military supplies, precious metals, cocoa, and textiles; travelers would exchange languages and cultures along the way. The goal of the travesía was in part to shine a light on the network of paths that, along with the culture of the Andean Aymara llama herders who still use them, is fading from existence.