Lac Castor is a Lake located in Belle-Rivière; Lac-Saint-Jean-Est, Quebec.

• Latitude: 48° 0' 18'' North   (decimal: 48.005)
• Longitude: 71° 58' 12'' West   (decimal: -71.97)
• Topography Feature Category: Lake
• Geographical Feature: Lac
• Canadian Province/Territory: Quebec
• Location: Belle-Rivière; Lac-Saint-Jean-Est
• GPS Coordinate Locator Map: Lac Castor Lat/Long