Saint-Montan is a commune in the Ardèche department in the Auvergne-Rhône-Alpes region in Southern France. It is located on the departm…Saint-Montan is a commune in the Ardèche department in the Auvergne-Rhône-Alpes region in Southern France. It is located on the departmental border with Drôme, which follows the course of the Rhône.