The Miguel Alemán dam did not stop the floods that continued to affect the Cuenca del Papaloapan region, so the dam had to be expanded by building the Miguel de la Madrid or Cerro de Oro dam.

This time, the construction of the Cerro de Oro dam affected about 26,000 indigenous people, mostly Chinantecs (also Mazatecs were affected). The indigenous people were relocated to other parts of the region and were even forced to move to the state of Veracruz.

The Cerro de Oro dam was inaugurated in 1988 by the president of Mexico, Miguel de la Madrid Hurtado.

The Cerro de Oro dam generated another artificial lake that is linked by a channel to Lake Miguel Alemán. To visit the dam it is recommended to visit the dam gates from where the Papaloapan River starts. The dam gates are only 18 km from Tuxtepec. From here you can get on a boat to visit the dam and lake. Another point where you can visit Lake Cerro de Oro is from Ojitlán.

How to get there: The gates of the Cerro de Oro dam are only 18 km from Tuxtepec. You must follow the road to Camelia Roja. The road passes next to the Papaloapan river.