12,000 years before present (YBP) the Laurentian ice sheet had melted to the east, creating an outlet for the Lake Erie basin at the Niagara Escarpment.

Holocene history of Lake Erie began with a flood of water over the Niagara Escarpment.

The flood created a channel in the moraines and bedrock lower water level in the Erie basin.

The level of Lake Algonquin dropped, ending the outflow through the Port Huron outlet.

For several thousand years Early Lake Erie did not receive water from the upper basins.

[11] The Buffalo Ridge shoreline in the eastern basin is 10 to 12 metres (33 to 39 ft) below the current river outlet.

[4] As the uplift continued, the North Bay Outlet rose, and the upper basin entered the stage of Lake Nipissing.

The Middle Stage ended around 5,300 YBP when drainage from Lake Nipissing was again diverted through the Port Huron outlet.

These underwater obstacles altered water circulation patterns,[11] forming new surface features, including Long Point, Ontario, and Presque Isle, Pennsylvania.

[4] When Lake Erie reached its present level 3,500 YBP, the southern tributary river that had created incised channels through the lacustrine sediment and glacial till during the low-water stages was flooded.