RIO NEGRO, a national territory of Argentina lying between 35' and 42° S. lat. and 62° 5o' and 72° 15' W. long., within the geographical area formerly known as Patagonia. It is bounded north by the territories of Neuquen and La Pampa, east by the Province of Buenos Aires and the Atlantic, south by the territory of Chubut and west by Chile and Neuquen. Area, about 77,500 sq.m. ; pop. (1914) 42,242 of whom approximately 15,00o were foreigners; 1934 estimate 65,674. That part of it lying between the Colorado and Negro rivers has much of the formation and characteristics of the "sterile pampas," but with irrigation the greater part of it can be utilized for agriculture and grazing. South of the Negro the country is arid, barren and lies in a series of sloping tablelands. Lake Nahuel-Huapi (20o sq.m. in area), lying partly in the territory of Neuquen (q.v.), is the principal lake of the region. However, there are several chains of lakes in the valleys of the Andes that are considered as rivals to Swiss scenery. The Atlantic coast-line of the territory has one deep indentation— the Gulf of San Matias—in the north bend of which is the port of San Antonio. Stock-breeding is the principal industry. Accord
ing to an estimate made in 1925 there were over 3,200,000 sheep, 100,500 cattle and 180,00o horses within the territory. Agricul ture is little developed, but irrigation, especially in the upper valley of the Rio Negro, is transforming arid regions into valu able soil, where grapes are raised. The capital is Viedma (pop., 1926 estimate, 5,000), on the right bank of the Rio Negro, 22 m. from its mouth and opposite Carmen de Patagones, a port of Buenos Aires. There are numerous small settlements along the Rio Negro and the railway extending inland from San Antonio, but the only other town of importance is Bariloche on the shore of Lake Nahuel-Huapi, western terminal of the railway from San Antonio. Other transportation facilities are furnished by the Great Southern railway which crosses the northern part of the territory.