The Arroyo Pepirí Miní o Yabotí Guazú (Este), known locally as the Yabotí Miní, forms the eastern branch of one of Misiones Province's most expansive and pristine river systems. This watercourse runs in a general north-south orientation through the heart of the Reserva de Biosfera Yabotí (RBY), ultimately joining its western counterpart — the Yabotí Guazú — approximately 10 kilometers north of their shared confluence with the Río Uruguay. The river flows over a rocky, bedrock-dominated channel ranging between 40 and 50 meters in width, carrying crystal-clear waters at a discharge of approximately 30 cubic meters per second. Situated within the departments of San Pedro and Guaraní in the center-east of Misiones Province, the watershed lies between 26°37'00" and 27°12'00" South latitude and 53°40'00" and 54°18'00" West longitude. The surrounding landscape is blanketed by Atlantic Forest in varying states of conservation, representing one of the most biologically rich and least disturbed jungle environments remaining in Argentina.