There were two periods when it was an independent lake, not associated with a larger body of water in the Huron basin.

[1] During its periods as an independent lake, its outlet was west through Grand River channel.

Well-defined beaches surround the outlet at an altitude 700 feet (210 m) above sea level,[2] To the north and west, they are higher because of isostatic rebound once the glaciers weight had been removed.

No proof of this has been found, but its outlet was near Syracuse, N. Y., where the situation favored large changes of lake level with relatively small oscillations of the ice front.

[1] When the ice barrier advanced into Lake Wayne, the water rose to the level of the Warren beach.

But the opening of a lower outlet along the Mohawk, ended the chance for another independent lake to arise in Saginaw Bay.

Only when the ice retreated from the Port Huron morainic system and Lake Saginaw merged again eastward and became part of Lake Wayne was the Grand River channel temporarily abandoned.

Through all previous changes, apparently without break or intermission from the first opening of the Imlay outlet, it had carried the overflow.

Later the ice advanced, closing the eastern outlet past Syracuse creating Lake Warren, which discharged through the Grand River channel.