Sonora is located 65 miles due south of San Angelo toward Del Rio on US 277 and I-10, where it is the seat of Sutton County.
In 1959 the city council commissioned plans for a series of flood-control dams; thirteen were constructed on the Devil's River Draw and Lowrey Draw by March 1961. By that time Sonora had a population of 2,633. During the 1970s oil and gas exploration peaked in the area. In 1977 an estimated 5,000 to 6,000 people lived in Sonora. But that year the boom ended, and the Santa Fe Railroad received permission to close its Sonora terminal. In 1984 the population was 4,500; 52 percent were Mexican American. The schools were integrated in 1970.
In 1990 the population had fallen to 2,751.