below sea level) and Iliamna Lake in Alaska 942 ft. (Though Crater Lake is the deepest lake in the United States and deeper than Lake Superior, Crater Lake's elevation is higher and consequently its deepest point is 4229 ft above sea level.)

While the temperature of the surface of Lake Superior varies seasonally, the temperature below 110 fathom is an almost constant 39 °F. This variation in temperature makes the lake seasonally stratified.