Whose lake is one of the Great Lakes, but the only one entirely in the United States?

Lake Michigan is unique among the Great Lakes because it lies entirely within the United States. It stretches along four states and plays a major role in shipping, fishing, and climate moderation. The lake is connected to the broader Great Lakes system and eventually to the Atlantic through the St. Lawrence River. Its vastness means it behaves almost like an inland sea in rough weather. Lake Michigan is one of North America’s most important freshwater bodies.