Lac du Marais is a Lake located in Mont-Valin; Le Fjord-du-Saguenay, Quebec.

• Latitude: 49° 2' 0'' North   (decimal: 49.0333741)
• Longitude: 70° 53' 19'' West   (decimal: -70.8886857)
• Topography Feature Category: Lake
• Geographical Feature: Lac
• Canadian Province/Territory: Quebec
• Location: Mont-Valin; Le Fjord-du-Saguenay
• Atlas of Canada Locator Map: Lac du Marais
• GPS Coordinate Locator Map: Lac du Marais Lat/Long