Colombia, Perú: Bajo Putumayo-CotuhéIn October 2019, a large multidisciplinary team of geologists, biologists, social scientists, and local residents explored the rivers, forests, and human communities around the junction of the Putumayo and Cotuh Rivers in the lowland Amazonian regions of Colombia and Peru. This report describes what is known to date about the regions geology, hydrology, and plant, fish, amphibian, reptile, bird, and mammal communities, as well as the present day and