The Río Bermejito is a fascinating and remote waterway winding through the Gran Chaco region of Chaco Province, Argentina. This river represents the southern branch of the historic Bermejo River, following the old bed of that great watercourse as it meanders through one of South America's most wild and impenetrable landscapes — the legendary El Impenetrable jungle. Intermittent and highly meandering in character, the Bermejito carries the hallmark red-colored sediments that give the Bermejo system its name, creating a turbid, sediment-rich environment that shapes every aspect of the fishery. The river's irregular flow patterns, driven by seasonal rainfall across the Gran Chaco, produce dynamic conditions that anglers must understand and respect. The surrounding riparian zone reflects the dense, subtropical dry forest of the Chaco, with dense vegetation pressing close to the banks and a landscape that remains one of the least-visited and most ecologically intact in all of Argentina.