Garonne (anc. Garumna), the principal river of south-west France, rises within the Spanish frontier in the Val d'Aran, at the base of Mount Maladetta, in the Pyrenees, 6142 feet above sea-level. About 26 miles from its source it enters the French territory in the dep. of Haute Garonne, and flows NE. and NW. until, joined by the Dordogne, 20 miles below Bordeaux, and widening afterwards into the Gironde estuary, it enters the Atlantic at the Pointe de Grave. The estuary, the largest in France, is nearly 50 miles long. The total length of the river is 346 miles ; it drains an area of 22,020 sq. m. Its navigation, which, however, is much impeded above Toulouse, commences for small craft at Cazeres ; ocean steamers go up to Bordeaux. Its principal affluents are the Tarn, Lot, and Dordogne, on the right; and on the left, the Save, Gers, and Baise. At Toulouse it is joined by the Canal du Midi, running eastward to the Mediterranean ; and the river's own canal lateral, starting also from Toulouse, runs 120 miles along the right bank.
Garonne, Haute, a dep. in the south of France, embracing portions of ancient Gascony and Languedoc. Area, 2428 sq. m.; pop. (1872) 479,362; (1901) 439,769. It is divided into the four arrondissements of Toulouse (the capital), Muret, St Gaudens, and Villefranche.