Conducted during the spring of 2003 in the Yavari and Yavari Mirin river valleys in the Amazonian lowlands of northeastern Peru, this survey provides both biological and social analyses offering a deep and multi-faceted picture of the area. Participating scientists examined four sites along the Yavari River. At each site, they surveyed a mix of forest types and microhabitats, both in the hilly uplands and on the Yavaris broad floodplain. Their report covers surveys of vascular plants, fishes, reptiles, and amphibians; birds, large mammals, and bats. The report also discusses the findings of a social assets inventory among nearby communities, in which teams used participant observation and conducted semi-structured interviews to quickly evaluate the assets of local communities, and estimate how the communities could be points of engagement for long-term participation in conservation efforts. The survey also reports on the main threats to the area, and offers recommendations for protection, management, and long-term conservation benefits.