As the nation’s most extensive freshwater system, the Great Lakes dominate the U.S. landscape. These five interconnected bodies of water straddle the U.S.-Canada border, playing a pivotal role in regional ecology, commerce, and water supply.
While none of the lakes lie entirely within U.S. territory, the shared stewardship of this vital resource underscores our partnership with Canada. Below, we detail each lake’s size, unique attributes, and ecological importance.
Lake Superior, bordered by Minnesota, Wisconsin, and Michigan—and Ontario to the north—remains the largest of the Great Lakes and the world’s largest freshwater lake by surface area. Its waters flow through the remaining lakes, ultimately reaching the Atlantic Ocean via the St. Lawrence River.
Michigan’s Lake Huron is the second‑largest of the system, defined by a remarkable 30,000 islands that grant it the longest shoreline among the Great Lakes. The lake’s name derives from the French term for the indigenous Wyandot people.
Lake Michigan, the third‑largest freshwater lake in the United States, is hydrologically linked to Lake Huron via the Straits of Mackinac. When considered together as Lake Michigan‑Huron, the combined surface area ranks as the world’s largest freshwater lake.
Lake Erie, the fourth‑largest Great Lake, sits between Ontario to the north and Michigan, Ohio, Pennsylvania, and New York to the south. The historic Erie Canal, which connected this lake to the Hudson River, transformed North American trade but also introduced invasive species that threatened native lake trout.
Lake Ontario, the smallest of the Great Lakes, lies east of the others and serves as the final conduit before waters exit to the Atlantic via the St. Lawrence River. Its name, from the Wyandot language, literally means “great lake.” Formed during the last glacial period about 14,000 years ago, it remains a key ecological and economic resource.
These lakes collectively support diverse ecosystems, provide drinking water for millions, and sustain regional economies—making their preservation essential for future generations.
