For fans of The Lost City of Z, Walking the Amazon, and Turn Right at Machu Picchu comes naturalist and explorer Paul Rosolie's extraordinary adventure in the uncharted tributaries of the Western Amazon--a tale of discovery that vividly captures the awe, beauty, and isolation of this endangered land and presents an impassioned call to save it.

In the Madre de Dios--Mother of God--region of Peru, where the Amazon River begins its massive flow, the Andean Mountain cloud forests fall into lowland Amazon Rainforest, creating the most biodiversity-rich place on...