There is some evidence that the Great Lakes were lower during the early expansion of humans across North America. Archaeologists have found traces of hunting blinds similar to those that can be seen in the Arctic today. This is not especially surprising since the general belief is that humans migrated in high numbers into North America from Asia across the land bridge that was exposed during the most recent ice age. The sea level was significantly lower and glaciers covered much of northern North America. It is clear that glaciers carved the basins in which the Great Lakes rest. The archaeological deposits under the lakes must have been deposited during a time prior to the filling of the basin with water yet at a period when ice was not within the basin where the deposits were found.
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