Inlet of the Gulf of Mexico .
Bounded by the Yucatán Peninsula , the Isthmus of Tehuantepec, and the southern part of the state of Veracruz , it covers about 6,000 sq mi (15,500 sq km). Major offshore oil fields were developed in the bay in the 1970s, and it became Mexico's principal oil-producing region. In 1979 an accident at an oil well there released some 3 million barrels of crude oil into the gulf; the government spent more than $100 million to bring the spill under control.