The Great Lakes, sometimes disambiguated as the Laurentian Great Lakes, are a collection of freshwater lakes located in northeastern North America, on the Canada–United States border, which connect to the Atlantic Ocean through the Saint Lawrence Seaway and the Great Lakes Waterway. Consisting of Lakes Superior, Michigan, Huron, Erie, and Ontario, they form the largest group of freshwater lakes on Earth, containing 21% of the world's surface fresh water. The total surface is 94,250 square miles, and the total volume is 5,439 cubic miles. The lakes are sometimes referred to as the North Coast or "Third Coast" by some citizens of the United States. The Great Lakes began to form at the end of the last glacial period around 10,000 years ago, as retreating ice sheets carved basins into the land and they became filled with meltwater. The lakes have been a major source of trade through their region, and are home to a large number of aquatic species. Many invasive species have been introduced due to trade in the area, and some threaten the region's biodiversity. Wikipedia [ - ]

The Great Lakes, sometimes disambiguated as the Laurentian Great Lakes, are a collection of... [ + ]