The French River to the Rhone is composed of two rivers, the Saone and the Isere. The Saone is a 545-kilometer long river that originates in the Vosges Mountains in eastern France and flows northwest into the Rhone. The Isere is a 515-kilometer long river that originates in the Alps in southeastern France and flows north into the Rhone. Together, these two rivers form the French River to the Rhone, which is an important waterway for transportation and commerce in France.