Sonora, a northern state of Mexico, bounded N. by the United States, E. by Chihuahua, S. by Sinaloa and W. by the Gulf of California. It is the second largest state in the republic, having an area of 76,900 sq. m. Pop. (1900), 221,682, a large part being Indian. The surface of the state is much broken by the Sierra Madre Occidental, which extends through it from north to south and covers its entire width with parallel ranges, enclosing fertile valleys. Four important rivers traverse the state from east to west with courses of 145 to 390 m. and discharge into the Gulf of California, viz.: the Altar, or Asuncion, Sonora, Yaqui and Mayo. The longest is the Yaqui, which has its source on the eastern side of the Sierra Tarahumare in Chihuahua and breaks through several ranges of the Sierra Madre before reaching the gulf near Guaymas. The smaller tributaries of these rivers of Sonora are often only dry canyons in the dry season. Agriculture has been developed only to a limited extent in Sonora, because of its aridity, lack of irrigation facilities, lack of railways and roads, and the unsettled state of the country. The soil of the sierra valleys is fertile, and when it is irrigated forage and cereal crops may be grown in abundance. Sugarcane, tobacco, maguey, cotton, in small quantities, and fruits are also produced. There are excellent pasture lands, especially in the upland districts, and stock-raising is an important and profitable industry. Land is held in large estates, some of them upwards of loo sq. m. in area. The mineral resources include silver, gold, copper, lead, tin, iron and coal, and mining is the chief industry. The lack of transportation facilities has been partly relieved by the construction of a branch of the Southern Pacific (American) from Nogales southward to Guaymas and the Sinaloa frontier, from which it has been extended to Mazatlan. Guaymas is the only port of importance on the coast, but it has a large trade and is visited by the steamers of several lines. The capital of the state (since 1882) is Hermosillo (pop. 190o, 17,618), on the Sonora river, 110 m. north of Guaymas, with which it is connected by rail. It suffered much in1865-1866from the savage struggle between Imperialists and Republicans, and in subsequent partisan warfare. Other important towns are Alamos (pop. 1895, 61 9 7), 13 2 m. E.S.E. of Guaymas, Moctezuma, 90 m. north of Hermosillo, and Ures, the old capital of Sonora and seat of a bishopric, 33 m. northeast of Hermosillo.
The first Jesuit mission in Sonora, founded among the Mayos in 1613, seems to have been the first permanent settlement in the state, although Coronado passed through it and its coast had been visited by early navigators. The hostility of certain tribes prevented its rapid settlement. Ures was founded in 1636, and Arizpe in 1648. Near the end of the century Sonora and Sinaloa were divided into two districts, in 1767 the Jesuit missions were secularized, in 1779 the government of the province was definitely organized by Caballero de Croix, and in 1783 Arizpe became the provincial capital. The bishopric of Sonora was created in 1781 with Arizpe as its seat. Up to this time the history of the province is little else than a record of savage warfare with the Apaches, Seris, Yaquis and other tribes. The development of rich gold and silver mines brought in more Spanish settlers, and then the record changes to one of partisan warfare, which continued down to the administration of President Porfirio Diaz.