It includes areas of southeastern Bolivia, southern and central Brazil, the entire country of Paraguay, most of Uruguay, and northern Argentina.

[6] The La Plata basin is bounded by the Brazilian Highlands to the north, the Andes Mountains to the west, and Patagonia to the south.

Politically, the basin includes part or all of the Brazilian states of Mato Grosso, Goiás, Minas Gerais, São Paulo, Mato Grosso do Sul, Paraná, Santa Catarina, and Rio Grande do Sul; the Bolivian departments of Santa Cruz, Chuquisaca and Tarija; the entire country of Paraguay; the western and central departments of Uruguay; and the Argentine provinces of Jujuy, Salta, Formosa, Chaco, Misiones, Tucumán, Santiago del Estero, Santa Fe, Corrientes, Córdoba, Entre Ríos, Buenos Aires, and La Pampa.

[7] The river discharges water into the Atlantic Ocean at an average rate of 22,000 cubic metres per second (780,000 cu ft/s), the majority of which comes from the Paraná.

Explorer Sebastian Cabot made a detailed study of the Río de la Plata and its tributaries and gave the river its modern name.

[4] The first European colony in the Platine region was the city of Buenos Aires, founded by Pedro de Mendoza on 2 February 1536.

[4] During the colonial era because of the lack of precious metals, the Platine basin was largely neglected by the Spanish Empire until the XVIII century when Portugal, after the founding of Colonia del Sacramento and the colonization of Rio Grande do Sul, and Britain threatened to expand into the estuary.

On the Negro River, in Uruguay, there are the Rincon del Bonete or Gabriel Terra Reservoir, and the Baygorria and Constitucion dams.