Lol, its amazing how many people dont know the history of this world.

I guess its hard though when you would have to be interested and care first. Because the powers that be are not going to put this in your basic highschool or college curriculum. Its like a big secret these days.

The massive weight and movement of this glacier gouged out the earth to form the lake basins. About 20,000 years ago, the climate warmed and the ice sheet retreated. Water from the melting glacier filled the basins , forming the Great Lakes.

So this site is likely even older than what they think.