largest and southernmost región of Chile. Named for Ferdinand Magellan, the Portuguese navigator, it became a colonial territory in 1853 and a province in 1929. It was given its present boundaries in 1961 and established as a region in 1974. It includes the provinces of Ultima Esperanza, Magallanes, Tierra del Fuego, and Antarctica. Magallanes y La Antarctica Chilena occupies an area of 50,979 square miles (132,034 square km) and includes the mainland west of the Argentine frontier, the numerous islands fronting the Pacific Ocean, the Archipiélago de Tierra Fuego, and the western half of Tierra del Fuego. The Chilean-claimed Antarctic region has an additional area of 480,000 square miles (1,250,000 square km). The territory west of the Andes Mountains is one of the world's most inhospitable: cool, rainy maritime conditions prevail throughout the year, and the yearly temperature range approximates 36° to 55° F (2° to 13° C). Many of the islands are barren; where forests do occur, the terrain prevents their commercial exploitation. Nevertheless, the channels, fjords, mountains, and glaciers make Magallanes a region of great scenic beauty. East of the Andes are extensive dry glacial plains covered with tussock grass, which support large sheep ranches that produce most of Chile's wool and some mutton. The development since 1945 of Chile's only oil fields in Tierra del Fuego, in the Strait of Magellan, and to the immediate north has broadened the economic base of Magallanes. Principal settlements are at Punta Arenas (q.v.), the regional capital; Puerto Natales; and Porvenir, on Grande Tierra del Fuego Island. Pop. (1992) excluding Chilean-claimed Antarctica, 143,486.