The Niger River is the largest river in West Africa at nearly 2,600 miles. The body of water crosses five countries--Benin, Guinea, Mali, Niger and Nigeria--originating in the Guinean Highlands. The mouth of the river is at the Gulf of Guinea in the Atlantic Ocean. The Niger is fairly clear, lacking the silt found in other African rivers, thanks to its rocky banks.
The Volta River originates at the point where its three tributaries--the Red, White and Black Volta--meet. Those rivers flow out of Burkina Faso and into Ghana, where they meet. The Volta flows into the man-made Lake Volta, which is Ghana's largest hydroelectricity source. From Lake Volta, the river flows into the Gulf of Guinea.
The Senegal River is the second-largest river in West Africa and forms a natural border between its namesake nation and Mauritania. The 1,100-mile long river stretches into the Mali highlands and descends into the Atlantic Ocean. The river holds an important role in providing water for electricity and drinking, however, overbuilding of dams has caused damage to ecosystems in the upper part of the river. There has been significant depletion of wildlife and an increase in water-borne illnesses.
The 700-mile Gambia River has more than just a natural significance. It was a major route of the pre-1850s slave trade. Africans would be transported down the river to James Island, a major exchange point for the slave industry, which has been designated a UNESCO World Heritage Site.
