The Rio Iaco is a significant river flowing through the state of Acre in western Brazil. It is a major watercourse with a considerable length, though sources vary between 480 and 693 kilometers. The river flows through a remote and sparsely populated region of the Amazon basin, bordering Peru. For paddlers, this suggests a wilderness experience with limited infrastructure and services. The river's character is defined by its role as a major Amazon tributary, implying a substantial water volume and a course through dense tropical rainforest. The aesthetic is one of a large, meandering river surrounded by expansive forest, with few signs of human development. The historical significance is noted by a photograph from 1913, indicating it has been a feature of the region for over a century. Planning a trip requires careful consideration of the remote location. Paddlers should be prepared for self-sufficient, multi-day expeditions with significant logistical challenges, including arranging transport to access points and managing all supplies. The international border with Peru adds a layer of complexity for any trip planning that might cross jurisdictions. Specific details on access points, hazards, seasonal conditions, water quality, recommended routes, water temperatures, facilities, or wildlife are not provided, underscoring the need for extensive, on-the-ground research and local guidance for any paddling attempt.