Luis Manuel Salamanca balanced on the tailgate of a rickety covered pickup truck, clinging onto the roof rack as it careened down the winding backroads of the Andes. It was dawn on May 22, 2018, and the Nudo de Almaguer—a fertile knot of dome-shaped mountains in southwestern Colombia known in English as the Colombian Massif—was beginning to stir.
As the fog lifted, a woman milking a bloated brown cow came into sight in a clearing. Red-and-white buses crammed with schoolchildren fought for passage with horse-drawn carts and cargo mules on narrow roads. More than 650 feet below, the Magdalena River rushed through a steep, emerald gorge fed by waterfalls tumbling down from every direction.
