Sonora, officially Estado Libre y Soberano de Sonora (Free and Sovereign State of Sonora), is one of 31 states that, with Mexico City, comprise the 32 federal entities of United Mexican States. It is divided into 72 municipalities; the capital city is Hermosillo. Sonora is bordered by the states of Chihuahua to the east, Baja California to the northwest and Sinaloa to the south. To the north, it shares the U.S.–Mexico border with the states of Arizona and New Mexico, and on the west has a significant share of the coastline of the Gulf of California.
Sonora's natural geography is divided into three parts: the Sierra Madre Occidental in the east of the state; plains and rolling hills in the center; and the coast on the Gulf of California. It is primarily arid or semiarid deserts and grasslands, with only the highest elevations having sufficient rainfall to support other types of vegetation.
Sonora is home to eight indigenous peoples, including the Mayo, the O’odham, the Yaqui, and Seri. It has been economically important for its agriculture, livestock (especially beef), and mining since the colonial period, and for its status as a border state since the Mexican–American War. With the Gadsden Purchase, Sonora lost more than a quarter of its territory. From the 20th century to the present, industry, tourism, and agribusiness have dominated the economy, attracting migration from other parts of Mexico.