Big Marsh is a Low vegetation located in Renfrew, Ontario and has an elevation of 272 meters.

• Latitude: 45° 37' 21'' North   (decimal: 45.6224999)
• Longitude: 77° 19' 14'' West   (decimal: -77.3205555)
• Topography Feature Category: Low vegetation
• Geographical Feature: Marsh
• Canadian Province/Territory: Ontario
• Elevation: 272 meters
• Location: Renfrew
• Atlas of Canada Locator Map: Big Marsh
• GPS Coordinate Locator Map: Big Marsh Lat/Long