Which rivers drain the andean region?

* The Amazon River: The Amazon River is the largest river in the world by volume and the second longest river in the world after the Nile River. It flows through Ecuador, Peru, Colombia, Venezuela, and Brazil before emptying into the Atlantic Ocean.

* The Magdalena River: The Magdalena River is the longest river in Colombia. It flows through the Magdalena Valley and empties into the Caribbean Sea.

* The Cauca River: The Cauca River is the second longest river in Colombia. It flows through the Cauca Valley and empties into the Magdalena River.

* The Orinoco River: The Orinoco River is the third longest river in South America after the Amazon and the Paraná rivers. It flows through Venezuela and Colombia before emptying into the Atlantic Ocean.

* The Paraná River: The Paraná River is the second longest river in South America after the Amazon River. It flows through Brazil, Argentina, and Paraguay before emptying into the Atlantic Ocean.

* The Uruguay River: The Uruguay River is the fifth longest river in South America. It flows through Brazil, Uruguay, and Argentina before emptying into the Atlantic Ocean.