RIVER GAMBIA, an important river of West Africa, and the only river of Africa navigable by ocean-going boats at all seasons for over 200 m. from its mouth. It rises in about 11° 25' N. and 12° 15' W., within 150 m. of the sea on the north-eastern escarpment of the Futa Jallon highlands, the massif where also rise the head-streams of the Senegal and some of the Niger tributaries, besides the Rio Grande and many other rivers flowing direct to the Gulf of Guinea. The Gambia, especially in its lower course, is very serpentine, and although the distance from the source to the mouth of the river is little more than 300 m. in a direct line, the total length of the stream is about 1000 m. It flows first N.N.E., receiving many left-hand tributaries, but about 12° 35' N. takes a sharp bend N.W. and maintains this direction until it leaves the fertile and hilly region of Bondu. The descent to the lower district is marked by the Barraconda rapids, formed by a ledge of rock stretching across the river. Between 30 and 50 m. above the falls the Gambia is joined by two considerable affluents, the Nieriko from the north and the Kuluntu or Grey river from the south. From the Barraconda rapids to the Atlantic the Gambia has a course of about 350 m. Throughout this distance the waters are tidal, and the river is navigable all the year round by boats drawing 6 ft. of water. At Yarbatenda, a few miles below Barraconda, the river has a breadth, even at the dry season, of over 300 ft., with a depth of 13 to 20 ft. From the falls to McCarthy's Island, a distance of 200 m., the river valley, which here presents a park-like appearance, is enclosed by low rocky hills of volcanic character. For 50 m. below the island, where the stream is about 800 yds. wide, the banks of the river are steep and thickly wooded. They then become low and are fringed with mangrove swamps. From Devil's Point, a sharp promontory on the north bank - up to which place the water is salt - the river widens considerably and enters the Atlantic, in about 13° N. and 16° W., by a broad estuary. Near the mouth of the river on the south side is St Mary's Island (3 m. long by 1 broad), and opposite on the north bank is Barra Point, the river being here contracted to 2 m. Eighteen miles lower down the distance from shore to shore is 27 m. There is a sand-bar at the entrance to the river, but at the lowest state of the tide there are 26 ft. of water over the bar. The Gambia is in flood from November to June, when the Barraconda rapids are navigable by small boats. Above the rapids the stream is navigable for 160 m. Politically the Gambia is divided between Great Britain and France - Britain possessing both banks of the river up to, but not including, Yarbatenda.
The Gambia was one of the rivers passed by Hanno the Carthaginian in his famous voyage along the west coast of Africa. It was known to Ptolemy and the Arabian geographers, and was at one time supposed to be a mouth of the Nile, and, later (18th century), a branch of the Niger. It was possibly visited by Genoese navigators in 1291, and was certainly discovered by the Portuguese c.1446, but was first explored for any distance from its mouth (1455) by the Venetian Alvise Cadamosto (q.v.), who published an account of his travels at Vicenza in 1507 (La Prima Navigazione per l'Oceano alle terre de' Negri della Bassa Ethiopia). Afterwards the Gambia became a starting-place for explorers of the interior, among them Mungo Park, who began both his journeys (1795 and 1805) from this river. It was not until 1818 that the sources of the Gambia were reached, the discovery being made by a Frenchman, Gaspard Mollien, who had travelled by way of the Senegal and Bondu. The middle course of the river was explored in 1851 by R.G. MacDonnell, then governor of the Gambia colony, and in 1881 Dr V.S. Gouldsbury also navigated its middle course. No native craft of any kind was seen above Barraconda. The more correct name of the river is Gambra, and it is so called in old books of travel.
See Mungo Park's Travels (London, 1799); G. Mollien, Travels ... to the Sources of the Senegal and Gambia ..., edited by T.E. Bowdich (London, 1820); the account of Dr Gouldsbury's journey in the Blue Book C 3065 (1881); also under the country heading below.
Note - this article incorporates content from Encyclopaedia Britannica, Eleventh Edition, (1910-1911)