Agua Prieta is a town in Agua Prieta Municipality in the northeastern corner of the Mexican state of Sonora. It stands on the Mexico–U.S. border, adjacent to the town of Douglas, Arizona. The municipality covers an area of 3,631.65 km2. In the 2010 census the town had a population of 79,138 people, making it the seventh-largest community in the state, and a literacy rate of 96.3%.