The plural form is used to denote that each basin was a separate unit, with a narrow strait connecting each.

As the ground continued to rebound from the weight of glacier, the Port Huron outlet began to again receive water, creating a temporary two-outlet lake.

[6] A few places along this route show a scoured bed that would require a similar volume and velocity of water movement as St. Clair River today.

[3] In the early part of this closing two-outlet stage a small discharge went by way of Illinois River at Chicago.

Thus, the known beaches of the Nipissing Great Lake are those formed during the period that the St. Clair valley served as the outlet.

This shallow excavation was made by a weak waterfall when the Erie basin was the main watershed feeding falls.

The name more precisely belongs to the older beach made by the Nipissing Great Lakes when the whole discharge passed through the Ottawa River.

Thus the beach from the earlier stage of the Nipissing Great Lakes in the south was flooded and destroyed.

Only the area in the northeast corner of Lake Superior still retains remnants of this first or original Nipissing beach.

[3] Along the east side of the Michigan ‘thumb’ the Nipissing beach has been cut away by the present lake.

[3] A shallow bay between Port Huron and Lakeport has a faint Algonquin beach at its back and a stronger one a mile (2 km) farther west.

Outside of these the Nipissing and lower beaches complete the filling of the old bay and bring the shore to a straight line.

[3] From Bay City northward to Saginaw, where the hinge line of the Algonquin and Nipissing beaches crosses the west shore of Saginaw Bay, the Nipissing beaches are sandy ridges 0.5 to 1 mile (0.80 to 1.61 km) from the lakeshore.

[3] In the Michigan and Huron basins the deformed portion of the Nipissing beach appears, as already stated to hinge on the same line as the Algonquin.

[3] A heavily developed shore line, called the Micmac beach, extends for 200 miles (320 km)below Quebec along the south side of the lower St. Lawrence.

Wave action at this level was evidently powerful and prolonged, for the sea cliff is in places 100 feet (30 m)high, cut in shale, and the wave-cut bench is unusually wide.