Laurentide ice sheet

Laurentide ice sheet
The maximum extent of North American ice sheets during the Last Glacial Maximum
Type	Continental
Location	North America
Highest elevation	Foxe-Baffin Dome: 2,200 to 2,400 metres (7,200 to 7,900 ft) above sea level Keewatin Dome: 3,200 metres (10,500 ft) above sea level[1]
Lowest elevation	Sea level
Terminus	North – Arctic Ocean East – Baffin Bay South – 40 degrees north latitude West – Rocky Mountains
Status	Remnants: Barnes Ice Cap, Penny Ice Cap[1]

The Laurentide ice sheet (LIS) was a massive sheet of ice that covered millions of square miles, including most of Canada and a large portion of the Northern United States, multiple times during the Quaternary glaciation epochs, from 2.58 million years ago to the present.^[2]

The last advance covered most of northern North America between c. 95,000 and c. 20,000 years before the present day and, among other geomorphological effects, gouged out the five Great Lakes and the hosts of smaller lakes of the Canadian Shield. These lakes extend from the eastern Northwest Territories, through most of northern Canada, and the upper Midwestern United States (Minnesota, Wisconsin, and Michigan) to the Finger Lakes, through Lake Champlain and Lake George areas of New York, across the northern Appalachians into and through all of New England and Nova Scotia.

At times, the ice sheet's southern margin included the present-day sites of coastal towns of the Northeastern United States, and cities such as Boston and New York City and Great Lakes coastal cities and towns as far south as Chicago and St. Louis, Missouri, and then followed the present course of the Missouri River up to the northern slopes of the Cypress Hills, beyond which it merged with the Cordilleran Ice Sheet. The ice coverage extended approximately as far south as 38 degrees latitude mid-continent.^[3]