Pilcomayo River

Pilcomayo is a river in central South America. It is the longest western tributary of the Paraguay River, stretching 1,100 kilometers (680 miles). It has a drainage basin area of 270,000 square kilometers (100,000 square miles) and a mean discharge of 200 cubic metres per second (7,100 cu ft/s).

The Pilcomayo silts up and splits into two main branches, north and south, along its course. After a while, these branches merge to form the Lower Pilcomayo.

The Pilcomayo River rises in the Andes mountain range's foothills in Bolivia's Oruro Department, east of Lake Poopó. The Pilcomayo is thought to have originated in the Jach'a Juqhu River. Aguas Calientes and Kachi Mayu are names given to the Jach'a Juqhu River upstream. The river is known as Pilcomayo from its confluence with the Chillawa (Chillahua). From there, it flows southeast through the departments of Chuquisaca and Tarija, then through the Argentine province of Formosa and the Gran Chaco plains of Paraguay, forming the majority of the border between these two countries before joining the Paraguay River near Asunción. The Río Pilcomayo National Park is located in Argentina. It also forms a short section of the Argentina–Bolivia–Paraguay border, just before the Argentina–Bolivia–Paraguay tripoint.

Length: 1,100 km (680 mi- shared with Argentina and Paraguay)