Sonora, a state of the Mexican Republic, occupying an area of 79,000 square miles between the lower spurs of the Andes and the shores of the Gulf of California. The flat regions near the coast. are very fertile, but are often broken up by marshy lagoons. The Sonora river, the Rio Colorado, the Mayo, and the Yaqui drain the country. Hermosillo is now the chief town, Ures and Arispe having formerly held that position.