Mexico currently operates two large coal-fired power stations named "José López Portillo" and "Carbón 2" located 30 miles (48 km) south of Piedras Negras.

These two coal-fired power plants are currently operated by Comisión Federal de Electricidad, the state-owned Mexican electric utility.

On June 15, 1850, a group of 34 men (commanded by Andrés Zapata, Gaspar Salazar and Antonio Ramírez) met with Colonel Juan Manuel Maldonado to give the news that they had created a pass point at Piedras Negras, to the right of the Rio Grande, south of Fort Duncan.

As it happened, the incursion was opposed and "repelled by a superior force of Negroes, Native Americans, and Mexicans who were waiting in ambush" inside Mexico.

The regional economy flourished and on December 1, 1888, it was granted city status; this time with the name of Ciudad Porfirio Díaz.

[citation needed] On April 24, 2007, an F4 tornado struck the city, killing three people there and seven in Eagle Pass, Texas.

Purón was supposed to run in the 2018 Mexican election on July 1 as a congressional candidate of the Institutional Revolutionary Party (PRI).

Sonia Villarreal, current mayor of Piedras Negras and fellow member of PRI, suspended her mayoral reelection campaign in response to Purón's murder to concentrate on her current duties, stating that "We don't (want) his name to be just one more added to the list of candidates who have been victims of these deplorable acts.

This region generates a large amount of the national production of coal, one of the most economically important non-metallic minerals in the state.

Activities last for 2–3 days and include concerts, food sales, acrobatic shows, a drive through town and a drawing with a brand new motorcycle as the grand prize.

The maquiladora industry employs almost 10,000 people in the municipality (about 25% of the Occupied Population), mainly engaged in the manufacture of automotive parts, electronic components and textiles.

La Central proudly hires directly and indirectly from the region where Piedras Negras, Nava, Morelos and Allende are located, Coahuila mainly.

It is part of the Northern Regional Production Management and delivers the generated energy to the Northeast Control Area through the 400 kV Lampazos I and II transmission lines, as well as a link to the Rio Escondido substation at the same voltage level.

Another important industrial branch is automotive metal, specialized in the manufacture of parts for suspension, which has been a fundamental pillar in the economy of the region, employing more than 2,000 people.

According to the BlackStones Maquiladora Industry Salary Survey, the daily wage for a general worker as of January 2006 was $47.85 to $87.60 while for an average command it is $173.91 to $205.00.