Sainte-Marie-du-Mont is a commune in the Manche department and in the region of Normandy in north-western France. The commune has 712 …Sainte-Marie-du-Mont is a commune in the Manche department and in the region of Normandy in north-western France. The commune has 712 inhabitants. Saint-Marie-du-Mont is located in the southeast of the Cotentin Peninsula, just north of the town of Carentan, and west of the fr:Baie des Veys Baie des Veys, the outlet of the Douve and the Vire.