Lac de l'Effroi is a Lake located in Réservoir-Dozois; Vallée-de-l'Or, Quebec and has an elevation of 365 meters.

• Latitude: 47° 42' 45'' North   (decimal: 47.7125)
• Longitude: 77° 20' 15'' West   (decimal: -77.3375)
• Topography Feature Category: Lake
• Geographical Feature: Lac
• Canadian Province/Territory: Quebec
• Elevation: 365 meters
• Location: Réservoir-Dozois; Vallée-de-l'Or
• Atlas of Canada Locator Map: Lac de l'Effroi
• GPS Coordinate Locator Map: Lac de l'Effroi Lat/Long