The Sarthe () is a river in western France. Together with the river Mayenne it forms the river Maine, which is a tributary to the river Loire. Its source is in the Orne department, near Moulins-la-Marche. It flows generally southwest, through the following departments and towns: Orne: Le Mêle-sur-Sarthe, Alençon Sarthe: Fresnay-sur-Sarthe, Beaumont-sur-Sarthe, Le Mans, Sablé-sur-Sarthe Maine-et-Loire: Châteauneuf-sur-Sarthe, Tiercé, Angers Its main tributaries are the Loir and the Huisne from the left, and the Vaige, the Erve and the Vègre from the right. Navigation The Sarthe has 20 weirs and locks. The channel is well marked and navigation is straightforward, except for the risk of shoals in certain sections. References External links River Sarthe with further maps and expanded details (by the author of 'Inland Waterways of France') Navigation details for 80 French rivers and canals (French waterways website section) Rivers of France Rivers of Maine-et-Loire Rivers of Orne Rivers of Sarthe Rivers of Normandy Rivers of Pays de la Loire Pays de la Loire region articles needing translation from French Wikipedia