CHIHUAHUA, a northern frontier State of Mexico, bounded N. and N.E. by the United States (New Mexico and Texas), E. by Coahuila, S. by Durango, and W. by Sinaloa and Sonora. The population in 1930 was 489,537, and the area, 94,831 sq.m. The surface of the State is in great part an elevated plain, sloping gently toward the Rio Grande. The western side, however, is much broken by the Sierra Madre and its spurs, which form ele vated valleys of great fertility. An arid sandy plain extending from the Rio Grande inland for 306 to 3 50m. is quite destitute of vegetation where irrigation is not used. The more elevated plateaux and valleys have the heavier rainfall, but over most of the State it is less than loin.; an impermeable clay substratum prevents its absorption by the soil, and the bare surface carries it off in torrents. The great Bolson de Mapimi, an enclosed de pression, in the south-eastern part of the State, was once con sidered to be an unreclaimable desert, but experiments with irrigation have shown its soil to be highly fertile. The only river of consequence is the Conchos, which flows north and north-east into the Rio Grande across the whole length of the State. In the north there are several small streams flowing northward into lakes. Agriculture has made little progress in Chihuahua, and the scarcity of water will always be a serious obstacle to its development out side the districts where irrigation is practicable. Stock-raising is an important industry in the mountainous districts of the west, where there is excellent pasturage for the greater part of the year. The principal industry of the State, however, is mining—its mineral resources including gold, silver, copper, mercury, lead, zinc and coal. The silver mines of Chihuahua are among the rich est in Mexico, and include the famous mining districts of Bato pilas, Chihuahuilla, Cosihuiriachic, Jesus Maria, Parral and Santa Eulalia or Chihuahua el Viejo. There are more than ioo of these mines, and the total annual yield at the end of the 19th century was estimated at $4,500,000. In 1922 Chihuahua stood first among the States in the production of lead, and second in the production of silver. The State is well served by three trunk-line railways and by several short branches to the mining districts.
Chihuahua originally formed part of the province of Nueva Viscaya, with Durango as the capital. In 1777 the northern prov inces, known as the Provincias Internas, were separated from the viceroyalty, and in i 786 the provinces were reorganized as intend encias, but Chihuahua was not separated from Durango until 1823. An effort was made to overthrow Spanish authority in 181o, but its leader Hidalgo and two of his lieutenants were cap tured and executed, after which the province remained passive until the end of the struggle. The people of the State have been active partizans in most of the revolutionary outbreaks in Mexico, and in the war of 1862-66 Chihuahua was loyal to Juarez. The principal towns are the capital Chihuahua, pop. (1930), 59,607; El Parral, 120m. S.S.E. of the State capital, in a rich mining district, with a population (1930) of 21,571; Ciudad Juarez across the Rio Grande from El Paso, pop. (1930) 4 2,8 24 ; Camargo, pop. (1930) 14,002; Santa Barbara, 12,943, and Jimenez, 120m. S.E. of Chihuahua, pop. (1930) 10,784.