Established on September 29, 1951 to protect the natural features (grasslands, marshes, creeks, lakes and forests), typical of the Humid Chaco ecoregion, the park is included in the Ramsar Convention's list of wetlands of international importance.

[2][3] The park occupies a large plain, which was formed when a depression in Paleozoic crystalline rocks was filled with organic and inorganic sediments, thus creating a sedimentary basin.

During the wet season, the river and its tributaries flood the nearby areas, creating large swaths of interconnected lakes and marshes, most of which are temporary.

One is savanna, which is dominated by the Caranday wax palm, an unofficial emblem of the area, towering over a dense cover of herbaceous plants (especially from the genus Scirpus).

[4] Higher lands are inhabited by such mammals as the gray brocket, capybara, peccary, howler monkey and puma; birds include chachalacas and rails.

The fish population includes species from the Hoplosternum that can use atmospheric air and thus tolerate droughts that frequently affect shallow water bodies in the area.