Ogooué River, stream of west-central Africa, flowing in Gabon for almost its entire course and draining an area of almost 86,000 square miles (222,700 square km). It rises in Congo (Brazzaville) on the eastern slopes of the Massif du Chaillu and flows northwest through Gabon past Franceville and Lastoursville; it then turns west and southwest past Booué, Ndjolé, and Lambaréné, collecting water from numerous lakes above Lambaréné. It forms a delta and empties into the Atlantic Ocean south of Port-Gentil, after a course of 750 miles (1,200 km).
The navigable parts of the river are heavily used for shipping goods, especially lumber, to the coast. Although interrupted by rapids and waterfalls along its upper course, the Ogooué is navigable as far as Lambaréné (114 miles [183 km] upstream) throughout the year. Its tributaries include the Ngounié, the Ivindo, the Mpassa, the Sébé, the Djadié, the Okano, the Abanga, the Lolo, and the Offoué. Between the Ngounié and the Ogooué rivers, the Chaillu Massif, the country’s main watershed, rises to more than 3,000 feet (900 m). The Lopé-Okanda Reserve, the landscape of which reflects a major migration route of Bantu and other peoples from the Ogooué River to east-central and southern Africa, was designated a UNESCO World Heritage site in 2007. Pierre Savorgnan de Brazza navigated the entire course of the upper Ogooué (1875–83), locating its source in 1877.