Location: it is situated in the northeast of Formosa province, in the riverside of Pilcomayo River, and limits with Paraguay.

Surface: It covers a 47.754 hectares surface.

Created: was created in 1951 to protect grass, marshes, gully, little lakes and rainforests in balcony, typical of the “Chaco Humedo” eco-region.

Plants: quebracho Colorado chaqueño, lapacho, urunday. oso melero, coaties, surucua comun, trepador castaño, choca listada, carpenter bird, garzas, caiman overo, caiman negro,

Animals: three types of monkeys: “cai”, “caraya” and “mirikina”. oso melero, coaties, surucua comun, trepador castaño, choca listada, carpenter bird, garzas, caiman overo, caiman negro, “boa curiyu” and aquatic snakes like “ñacanina”. In the coasts develop large “pehuaiozales” and “pirizales” where “carpinchos”, “coipos” and nutres can be saw.

Characteristics: PN Río Pilcomayo (Rio Pilcomayo National Park) protects grass, marshes, gully, little lakes and rainforests in balcony.

Rio Pilcomayo National Park had been included in the Most Important “Humedales” of the World List (Ramsar Convention).

Because of its flatness there are many marshes, lakes and floodable grasslands in the park. The whole is liable to flooding in the rainy season (Summer months) and dries out in Winter. Slightly higher elevations support chaco woods on hummocks - all this leads to a nice variety of habitats with the resulting richness of Biodiversity. The "white" palm, also known as the Caranday (Copernicia alba) grows to 14m in height. Its foliage is a greyish green.

Many species of birds use it for their nesting - monk parakeets, the pale-crested woodpecker and the black-hooded parakeet, the last two in hollows in the trunks. The large free-tailed bulldog bat roosts in the hanging dead fronds. In these open spaces one can encounter rheas or groups of the red-legged seriema. The manned wolf is frequently seen here, a mousing "fox-on-stilts" which is endangered everywhere. It is of solitary habits, timid and nocturnal, resting up in patches of dense grass during the day. Its blackish mane, huge ears, reddish coat, a slender muzzle and a short white tail are enough characteristics to recognise it by.