High Quality Content by WIKIPEDIA articles! The Okavango River is a river in southwest Africa. It is the fourth-longest river system in southern Africa, running southeastward for 1,600 km (990 mi). It begins in Angola, where it is known as the Cubango River. Further south it forms part of the border between Angola and Namibia, and then flows into Botswana, draining into the Moremi Game Reserve.