Which 1,528 km river is the main river of Colombia?

The 1,528 km river that is Colombia’s main river is the Magdalena River.

The Magdalena rises in southern Colombia’s Colombian Massif and flows generally north through the broad valley between the Central and Eastern Cordilleras of the Andes. It eventually reaches the Caribbean Sea at Barranquilla, making it the country’s principal north–south waterway and the largest river system of the northern Andes.

For centuries, the river served as Colombia’s most important transport route between the interior and the Caribbean coast. Cities including Neiva, Honda, Barrancabermeja, Mompox and Barranquilla developed along its course or within its floodplain. Its valley also supports farming, wetlands, fisheries and major oil-producing areas.

The Magdalena’s largest tributary is the Cauca River, which joins it in the lower basin. That relationship causes frequent confusion: the Cauca is geographically important, but it is not Colombia’s main river. The Meta is a major Orinoco tributary, while the Atrato flows north toward the Caribbean but is much shorter.