CHACO, a territory of northern Argentina, part of a large district known as the Gran Chaco, bounded N. by the territory of Formosa, E. by Paraguay and Corrientes, S. by Santa Fé, and W. by Santiago del Estero and Salta. The Bermejo river forms its northern boundary, and the Paraguay and Paraná rivers its eastern; these rivers are its only means of communication. Pop. (1895) 10,422; (1904, est.) 13,937; area, 52,741 sq. m. The northern part consists of a vast plain filled with numberless lagoons; the southern part is slightly higher and is covered with dense forests, occasionally broken by open grassy spaces. Its forests contain many species of trees of great economic value; among them is the quebracho, which is exported for the tannin which it contains. The capital, Resistencia, with an estimated population of 3500 in 1904, is situated on the Paraná river opposite the city of Corrientes. There is railway communication between Santa Fé and La Sabana, an insignificant timber-cutting village on the southern frontier. In the territory there are still several tribes of uncivilized Indians, who occasionally raid the neighbouring settlements of Santa Fé.