[Condor51]

Weird map?? It shows all the Great Lakes gone.

Yet the deepest part of Lake Michigan is 923ft and Superior is 1,333 ft - so I don't 'get' the 330 ft lower water level making them disappear??

[blam]

"Weird map?? It shows all the Great Lakes gone. "

The Great Lakes were covered by ice that was 1-2 miles thick during the Ice Age. I believe it was the movement of these glaciers that 'carved-out' the Great Lakes.