Río Tragadero is a permanent watercourse located in the eastern part of Chaco Province, Argentina. It originates in the bañados de Ñacurutú — large wetland areas — where it begins as arroyo Tragadero before developing into a full river. Over its approximately 100-kilometer length, it drains several lagoons along its course, including lagunas Conchas, Desayuno, and Cuchara. Its most significant tributary is estero Camba, which connects via arroyo Quintana just upstream of Colonia Benítez. In its lower reaches, the river borders the southern edge of Colonia Benítez and passes through the northern periurban zone of Gran Resistencia. It ultimately joins the río Negro roughly 650 meters before that river empties into riacho Barranqueras, a distributary of the río Paraná.

The river is considered one of the best-preserved waterways in the Gran Resistencia area, with a character similar to the nearby río Negro but notably healthier and more intact. The surrounding landscape reflects the Chaco Húmedo ecoregion, characterized by dense riparian vegetation and rich biodiversity. Historically, the river was navigable enough that timber companies used it to transport logs, though water levels have fluctuated over time and are sensitive to local rainfall patterns.

Paddling on Río Tragadero is an established local activity. Canoe and kayak outings are a recognized form of recreation on the river, with paddlers navigating its curves through the natural corridor near Colonia Benítez. Accommodation options exist directly on the riverbank in Colonia Benítez, including at least one riverside cabin equipped with basic amenities such as a deck overlooking the water, making it a practical base for multi-day paddling trips. The river's winding course through intact Chaco Húmedo vegetation provides a visually distinctive paddling environment.

Yacarés (caimans) are present in the area and should be considered a wildlife hazard. Access is possible from Colonia Benítez and Gran Resistencia, the nearby population centers.