Which Great Lake is the largest lake entirely in one country by surface area?

Which Great Lake is the largest lake entirely in one country by surface area? Lake Michigan.

Lake Michigan is the largest lake by surface area located entirely within a single country. Its roughly 22,300 square miles (57,800 square kilometres) lie wholly within the United States, across Illinois, Indiana, Michigan, and Wisconsin. It is the only one of the five Great Lakes situated entirely in the United States.

The lake formed as glaciers scoured and deepened the Great Lakes basin during the Ice Age. It is about 307 miles long and reaches a maximum depth of approximately 923 feet. Lake Michigan connects to Lake Huron through the Straits of Mackinac; because the two share the same water level and are hydrologically connected, scientists sometimes refer to them together as Lake Michigan-Huron.

That connection creates a frequent source of confusion. Michigan-Huron has a larger combined surface area than Lake Superior, but the two lobes are conventionally treated as separate Great Lakes. Lake Baikal is deeper and contains more water, yet its surface area is much smaller than Michigan's.