The Marten River flows into the lake and the Temagami River flows through the lake.

It is a man made lake originally created by damming to permit logging drives.

Red Cedar Lake now serves as a man-made reservoir for hydro-electric generating stations and the water level may vary because of this.

Red Cedar Lake contains fish populations of walleye, northern pike, smallmouth bass, yellow perch, whitefish, and lake trout.

This Northern Ontario geographical article is a stub.