Devils Lake is a lake in the U.S. state of North Dakota. It is the largest natural body of water and the second-largest body of water in North Dakota after Lake Sakakawea. It can reach a level of 1,458 ft before naturally flowing into the Sheyenne River via the Tolna Coulee. On June 27, 2011, it reached an unofficial historical high elevation of 1,454.3 ft…Devils Lake is a lake in the U.S. state of North Dakota. It is the largest natural body of water and the second-largest body of water in North Dakota after Lake Sakakawea. It can reach a level of 1,458 ft before naturally flowing into the Sheyenne River via the Tolna Coulee. On June 27, 2011, it reached an unofficial historical high elevation of 1,454.3 ft. The cities of Devils Lake and Minnewaukan take their name from the lake as does the Spirit Lake Reservation, which is located on the lake's southern shores.