The western and southern portions of Sonora are generally flat. In the south, between the rivers Mayo and Yaqui and the Presidio of Buena Vista, there is a fruitful region, whose productiveness is enhanced by a number of small lakes formed during the rainy season on the levels, which are used by the careful agriculturists for the irrigation of their farms. On the eastern boundary of the State, the ridges of the Cordillera begin to rise, until they tower into the massive mountains which form the Sierra Madre, among the spurs of which many valuable metallic deposits have been discovered. The fine and productive vallies of Bavispe, Oposura, Sonora and Dolores are found in the neighborhood of this mountain country.
Sonora is divided into two Departments:
1st. The Department of Arispe, with three cantons, viz: Arispe, Oposura and Altar.
2nd. The Department of Horcasitas, with three cantons, viz: Horcasitas, Ostimuri, and Petic.
The chief rivers are the Mayo, the boundary in the direction of Sinaloa; the Yaqui or Hiaqui; the Rio Grande de Bavispe; Oposura; Sonora; Dolores; Guayamas; Rio de la Ascencion; San Ignacio; Gila; San Francisco or Rio Azul; San Pedro; Santa Maria and the Rio Colorado.
The climate of Sonora is warm throughout the year; but the early spring is subject to remarkable and rapid changes of temperature, and to sudden variations of wind between the north and east. From April to the end of September the thermometer ranges between 75° and 84° Fahrenheit.
A large portion of Sonora is occupied by Indian tribes, some of which are partially agricultural where they have been brought into contact with the whites; but the greater portion may be regarded as belonging to the wild nomadic bands which have hitherto harassed the northern settlements of Mexico. In the eastern part of the State, on the banks of the Sonora and Oposura, and in the vicinity of the town of Arispe and the mineral region of Nocasari, we find large numbers of the Opátas. North of the Ascencion, and stretching far inland from the coast, are the Pimos Altos, the most northerly bands that have submitted to the influences of Christianity or of partial civilization. The nomadic tribes in the north and north-east of the State are Papayos or Papábi-Otawas, the Yumas, the Cucapas or Cupachas, the Cajuenches, the Coanópas, the Apaches Tontos, the Cocomaricopas, the Pimo Galenos, the Apaché Gilenos, Apaché Mimbreños, and Apaché Chiricaguis. Of all these wild and savage tribes, the Apachés are the most uncontrollable.
The trade of Sonora is chiefly carried on at Guyamas, in latitude 27° 40´ N. and 114° W. longitude from Paris,—one of the best harbors in West Mexico, in a healthy region, containing about 3,000 inhabitants;—and at Petic, forty leagues north north-east from Guyamas, in about 29° 20´ of north latitude. The latter town, containing about 8,000 inhabitants, is the depôt for goods imported through the port of Guyamas which are designed for the northern districts of Mexico. Besides these two important places, there are the towns of San Miguel Horcasitas, with 2,500 inhabitants; Arispe, with 3,000; San José de Guyamas 350 to 400; Bayoreca; Onabas; Presidio de Buena Vista; El Aguáge; Ures; Babiacora; Banamitza; Batuc; Matape; Oposura; Presidio de Bavispe; Presidio de Fronteras; San Ildefonso Cieneguilla; Presidio de Santa Gertrudis del Altar; Oquitoa; Presidio de la Santa Cruz; Presidio de Tuscon; and Presidio de Tubac.
The mineral characteristics are similar to those of Sinaloa.