A view of Yasuní National Park and the Río Napo, in Ecuadoran Amazonia. Credit: Misha Vallejo Prut The first signs of the river were the volcanoes, armored with ice. I saw them from the plane as I was flying down from Quito, Ecuador’s high-altitude capital, into Amazonia, that vast region of rainforest, spread across nine countries, that is drained by the Amazon River and its tributaries. The glaciers of Cayambe, Antisana, and Cotopaxi are the sources of one of those tributaries—the Río Napo.