Lac Dumais is a Lake located in Lac-Ashuapmushuan; Le Domaine-du-Roy, Quebec and has an elevation of 422 meters.

• Latitude: 49° 44' 53'' North   (decimal: 49.7480556)
• Longitude: 73° 54' 19'' West   (decimal: -73.9052778)
• Topography Feature Category: Lake
• Geographical Feature: Lac
• Canadian Province/Territory: Quebec
• Elevation: 422 meters
• Location: Lac-Ashuapmushuan; Le Domaine-du-Roy
• Atlas of Canada Locator Map: Lac Dumais
• GPS Coordinate Locator Map: Lac Dumais Lat/Long