OGOOU RIVER

also spelled Ogowe, 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 Boou, Ndjol, and Lambarn, collecting water from numerous lakes above Lambarn. 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 Ogoou is navigable as far as Lambarn (114 miles upstream) throughout the year. Its tributaries include the Ngouni, the Ivindo, the Mpassa, the Sb, the Djadi, the Okano, the Abanga, the Lolo, and the Offou. Between the Ngouni and the Ogoou rivers, the Chaillu Massif, the country's main watershed, rises to more than 3,000 feet (900 m). Pierre Savorgnan de Brazza navigated the entire course of the upper Ogoou (187583), locating its source in 1877.