To recap, the river flows into Lake Superior and harbors one of the last remaining runs of coaster brook trout. Coasters are brook trout that are reared in rivers and streams but live the majority of their lives in Lake Superior. In those deep, cold waters they grow to substantial proportions – far larger than brookies that live out their lives inland. In the fall, when they reach sexual maturity, coasters return to the rivers and streams from which they came to spawn. Coasters are the only migratory salmonid native to Lake Superior.