The Mare River is a river in the Hérault département of southern France, which rises in the Caroux-Espinouse hills.The river's source is above Castanet-le-Haut in the Parc naturel régional du Haut-Languedoc. The river passes through Saint-Gervais-sur-Mare and Villemagne-l'Argentière, before joining the Orb at Hérépian.