Saone (Anc. Arar; In The Middle Ages Se-Gona Or Saucona), a river of France, which has its source at Vioménil, in the S. W. part of the department of Vosges, flows generally S. through the departments of Haute-Saône, Côte d'Or, and Saône-et-Loire, forms the boundary between those of Rhône and Ain, and unites with the Rhône at Lyons. Its length is 280 m., of which 190 m. are navigable for steamboats. The town of Gray is the head of navigation at the ordinary height of the river, but during an overflow large rafts, loaded with staves, iron, and other heavy produce, descend from the department of Vosges to Gray. Its principal affluents are the Oignon, Doubs, and Seille from the left, and the Ouche and Grone from the right. The Burgundian, Central, and Rhône and Rhine canals connect it with the Rhine and the Seine. Though usually a gentle stream, it has at times been subject to destructive floods; several of these are on record, including one in 1840 which produced great loss of property and life at Lyons.