Lac Tiernish is a Lake located in Lac-Walker; Sept-Rivières, Quebec.

• Latitude: 50° 5' 30'' North   (decimal: 50.0916667)
• Longitude: 67° 34' 29'' West   (decimal: -67.5747222)
• Topography Feature Category: Lake
• Geographical Feature: Lac
• Canadian Province/Territory: Quebec
• Location: Lac-Walker; Sept-Rivières
• Atlas of Canada Locator Map: Lac Tiernish
• GPS Coordinate Locator Map: Lac Tiernish Lat/Long