Chaco Region (El Gran Chaco) is a vast alluvial plain in the interior of South America which is shaped like a cone. The Chaco region occupies more than 100,000 square miles of western Paraguay, eastern Bolivia, and northern Argentina. It is extremely flat, rising only gently from the Paraná-Paraguay river system in the east to western Argentina and the lowlands of eastern Bolivia. It is divided by rivers into three sections: the Chaco Austral between the Salado and Bermejo rivers, the Chaco Central between the Bermejo and Pilcomayo rivers, and the Chaco Boreal from the Pilcomayo to just north of the Paraguay-Bolivia border.
During the summer, many areas are drenched with rain, leaving lagoons, swamps, and rivulets overflowing in every direction. In winter these same areas are arid wastelands cut irregularly by thorn forests. The region is home to a vast array of fauna, including jaguars, tapirs, parrots, and a species of peccary long thought to be extinct. Usually cited as one of the continent's last great wildernesses, much of it remains sparsely settled and infrequently visited, although it produces timber, livestock, and cotton.
In pre-Columbian times the Chaco region was synonymous with the unknown. The pre-Hispanic inhabitants of the Altiplano simply called it chacu, a Quechua word meaning "great hunting ground." The Guarani from Paraguay and Brazil crossed it to trade with Andean peoples. Sixteenth-century Spanish explorers followed the Guaranis across the Chaco to Peru; but after the Chaco peoples, including the Mocobís, Abipones, and Tobas, acquired horses and resisted Spanish incursions, the Spaniards forgot the route and rarely ventured into the region.
In the eighteenth century Spanish ranchers and timber merchants penetrated the Chaco. Late in the century, government expeditions probed the interior, and minor missions were sent to the Abipones and Mocobís. During the late nineteenth century, venture capitalists from Argentina and Europe sought to open the Chaco to commercial exploitation. They focused primarily on the region's hard-woods—lapacho, curupay, petereby, and especially quebracho (a source of tannin for curing leather). Their efforts were hampered by the climate, terrain, and native resistance. The local communities of the Argentine Chaco were finally subdued in the 1880s, those of the Bolivian Chaco in the 1890s. Only Mennonite farmers, who came from Eastern Europe to the Paraguayan Chaco in the beginning of the twentieth century seemed to make the land thrive. They raised cattle and grew cotton.
Border disputes—and a lingering rumor that the region possessed sizable reserves of petroleum—led to the Chaco War (1932–1935), in which Paraguay bested Bolivia, gaining most of the Chaco Boreal, at the cost of tens of thousands of lives.
After the war, colonization increased, especially in the eastern part of the Chaco. Ranches and farms gradually replaced military posts. The Chaco indigenous groups—Chiriguanos, Makas, Nivaklés, Lenguas, Ayoreos, and others—hired out as wranglers or day-laborers chiefly on Mennonite lands. National and foreign companies exploited the Argentine Chaco. Oil companies explored the Chaco without success. By the late 1980s, stockraising, dairy farming, and cotton growing had transformed the Argentine Chaco and the eastern Paraguayan Chaco. The traditional isolation and natural purity of these areas were becoming things of the past. Daily commuters from Asunción now crossed a new bridge over the Paraguay River to Chaco communities, and Chaco products traveled to Asunción. Nevertheless, vast stretches of the Chaco, especially in the center and west, were still nearly empty of human population.
In September of 1995, the Bolivian government established the Kaa-Iya National Park (Parque Nacional y área natural de manejo integrado Kaa-Iya del Gran Chaco), home to Latin America's most diverse population of mammals. Developed in partnership with the Guaraní peoples known as Isoceño, and the Wildlife Conservation Society, the 3.44 million hectare Kaa-Iya National Park is managed solely by the indigenous people themselves through the Capitanía de Alto y Bajo Isoso (CABI).
Martin Dobrizhoffer, An Account of the Abipones: An Equestrian People of Paraguay, 3 vols., translated by Sara Coleridge (1822; repr. in 1 vol., 1970).
Pedro Lozano, Descripción corográfica del Gran Chaco Gualambra (1941).
Alfred Métraux, "Ethnography of the Chaco," in Handbook of South American Indians, vol. 1, edited by Julian H. Steward (1946).
Juan Belaieff, "The Present-Day Indians of the Gran Chaco," in Handbook of South American Indians, vol. 1, edited by Julian H. Steward (1946), pp. 197-370, 371-380.
David H. Zook, The Conduct of the Chaco War (1960).
Harry Robinson, Latin America: A Geographic Survey (rev. ed., 1967), pp. 432-435, 464-466.
Luis Jorge Fontana, El Gran Chaco: Estudio preliminar de Ernesto J. A. Maeder (1977).
Andrew Nickson, Historical Dictionary of Paraguay (rev. ed., 1993), pp. 111-123.
Andrew Taber, Gonzalo Navarro, Miguel Angel Arribas. "A New Park in the Bolivian Gran Chaco—An Advance in Tropical Dry Forest Conservation and Community-based Management." Oryx 31, no. 3 (July 1997): 189-198.
James Schofield Saeger
Thomas L. Whigham