Piedras Negras (Spanish pronunciation: [ˈpjeðɾas neɣɾas]) ( Black stones ) is a city and seat of the surrounding municipality of the same name in the Mexican state of Coahuila. It stands at the northeastern edge of Coahuila on the U.S.-Mexico border, across the Río Bravo (Rio Grande) from Eagle Pass in the U.S. state of Texas. In the 2012 census the city had a population of 139,169 people, which accounted for 91 percent of its municipality's total population of 152,806. The municipality's relatively small area includes some minor localities outside the city limits.