Deux-Montagnes is a suburban municipality in Southwestern Quebec, Canada on the north shore of the Rivière des Mille Îles where it flow…Deux-Montagnes is a suburban municipality in Southwestern Quebec, Canada on the north shore of the Rivière des Mille Îles where it flows out of Lake of Two Mountains. It is part of the Deux-Montagnes Regional County Municipality in the greater Montreal region. It is located 40 kilometres from Montreal.