DOUBS, a river of eastern France, rising in the Jura at the foot of the Noirmont ridge at a height of 3074 ft. and flowing into the Saône. Its course is 269 m. in length, though the distance from its source to its mouth is only 56 m. in direct line; its basin has an area of 3020 sq. m. Flowing N.E. the river traverses the lake of St Point and passes Pontarlier; thenceforth its course lies chiefly through wooded gorges of great grandeur. After skirting the town of Morteau, below which it expands into the picturesque lake of Chaillexon and descends over the Falls of the Doubs (88 ft. in height), the river for about 28 m. forms the frontier between France and Switzerland. Flowing into the latter country for a short distance, it turns abruptly west, then north, and finally at Voujeaucourt, south-west. Just below that town the river is joined by the canal from the Rhone to the Rhine, to accommodate which its course has been canalized as far as Dole. Till it reaches Besançon which lies on a peninsula formed by the river, the Doubs passes no town of importance except Pontarlier. Some distance below Besançon it enters the department of Jura, passes Dole, and leaving the region of hill and mountain, issues into a wide plain. Traversing this, it receives the waters of the Loue, its chief affluent, and broadening out to a width of 260 ft., at length reaches the Saône at Verdun. Below Dole the river is navigable only for some 8 m. above its mouth.