Brazil's Cândido Rondon is the greatest tropical explorer in history. Between 1890 and 1930, he navigated scores of previously unmapped rivers and mountains, hacked his way through jungles so inhospitable that even native peoples had avoided them, and led Theodore Roosevelt and his son on their celebrated "River of Doubt" journey from 1913 to 1914. Rondon, himself of Indigenous descent, devoted his life to documenting the region's flora and fauna, advocating for the peoples who inhabited the rainforest, and lobbying for the creation of national parks. Despite his many achievements-which include laying down a 1,200-mile telegraph line through the heart of the Amazon and three Nobel Peace Prize nominations-Rondon has never before received his due. Into the Amazon is the first comprehensive biography of his remarkable life and career.