The Dead River is a 43.2-mile-long (69.5 km) river in Marquette County, Michigan. It is the largest tributary to Lake Superior in Marquette County, with a watershed approximately 163 square miles (420 km2) in size, and an estimated discharge of 199.6 cubic feet per second (5.65 m3/s). The river flows east-southeast from its source in the McCormick Wilderness in western Marquette County to its mouth at Lake Superior in the city of Marquette. It is a state-designated trout stream.