[1] The river originates in the mountains to the east of the Isthmus of Tehuantepec, a lowland corridor between the Gulf of Mexico and the Pacific Ocean.

[2] The river provides water to the township of Santa María Chimalapa and to Cuauhtémoc, the most important arable and livestock region of the state of Oaxaca.

[3] From 1731 to 1747, the forests around Santa María Chimalapa were an important source of giant pines, used for masts and beams by the Spanish Navy.

[4] The Zoque Forest today is under pressure from forestry and forest fires, human population growth, agrarian conflict, cattle production, subsistence hunting and illegal trafficking of threatened species, development and infrastructure projects and narco-trafficking.

[5] In June 2008 the State of Oaxaca was considering construction of a storage dam in the Río El Corte Basin in the Chimalapa sub-region, with the potential to irrigate 100,000 hectares of the Isthmus of Tehuantepec and to supply water to the Salina Cruz Refinery.