Mattress Island is a Island located in Algoma, Ontario and has an elevation of 434 meters.

• Latitude: 46° 54' 36'' North   (decimal: 46.9099999)
• Longitude: 83° 35' 11'' West   (decimal: -83.5863888)
• Topography Feature Category: Island
• Geographical Feature: Island
• Canadian Province/Territory: Ontario
• Elevation: 434 meters
• Location: Algoma
• Atlas of Canada Locator Map: Mattress Island
• GPS Coordinate Locator Map: Mattress Island Lat/Long