bay of the Gulf of Mexico, southern Mexico. It is bounded by the Yucatán Peninsula to the east, by the Isthmus of Tehuantepec to the south, and by southern Veracruz to the west. The bay covers an area of about 6,000 square miles (15,540 square km) and generally cannot be entered by vessels drawing more than 9 feet (3 metres). Rivers flowing into the bay include the Papaloápan, Coatzacoalcos, Grijalva, Usumacinta, and Candelaria. Términos Lagoon and other lagoons and swamps dot the low-lying shores along the bay. Highways connect the major port cities of Veracruz, Coatzacoalcos, Ciudad del Carmen, and Campeche.

Major offshore oil wells were drilled in the bay during the 1970s, and it became the highest oil-producing region in Mexico in the early 1980s. International attention was drawn to the area in mid-1979, when the Ixtoc 1 well blew out and released an estimated 3,000,000 barrels of crude oil (oil spill) into the Gulf of Mexico, some of which washed up onto beachfronts in Texas, 600 miles (965 km) away, before the well was finally capped early the next year. The Mexican government spent an estimated $132,000,000 to bring the spill under control. An oil pipeline connects the bay area to Coatzacoalcos on the coast near the city of Minatitlán, where there are pipeline connections and a tanker terminal.