Usumacinta River

The Usumacinta River is a river in southeastern Mexico and northwestern Guatemala. It is formed by the junction of the Pasión River, which arises in the Sierra de Santa Cruz and the Salinas River, also known as the Rio Chixoy, or the Rio Negro, which descends from the Sierra Madre de Guatemala. It defines part of the border between Guatemala and the Mexican state of Chiapas, then continues its northwesterly course, meandering through the Mexican state of Tabasco to the Gulf of Mexico.