Pilcomayo is a department in the Argentine province of Formosa. Its capital is Clorinda, the second most populous city in the province. Pilcomayo has a surface of 5,342 km² and a population of 78,114 according to the 2001 census [INDEC]. Other communities in Pilcomayo include Laguna Blanca, Laguna Naick Neck, Riacho He-Hé and Siete Palmas. The Pilcomayo River National Park (Parque Nacional Río Pilcomayo) is about 45 kilometers west of Clorinda, crossed by the Pilcomayo River.
Coordinates: 25°17′10″S 57°43′21″W / 25.28611°S 57.72250°W