Duff Lake is a Lake located in Cassiar Land District, British Columbia and has an elevation of 1233 meters.

• Latitude: 59° 47' 17'' North   (decimal: 59.7880556)
• Longitude: 136° 5' 56'' West   (decimal: -136.098889)
• Topography Feature Category: Lake
• Geographical Feature: Lake
• Canadian Province/Territory: British Columbia
• Elevation: 1233 meters
• Location: Cassiar Land District
• Atlas of Canada Locator Map: Duff Lake
• GPS Coordinate Locator Map: Duff Lake Lat/Long