What geographical feature separates the Upper and Lower Peninsulas of Michigan?

The Straits of Mackinac serve as the geographical feature that separates Michigan's Upper and Lower Peninsulas. This narrow waterway connects Lake Michigan to Lake Huron and is a significant landmark in the state. The straits are about five miles wide and are not only crucial for water navigation but also play a key role in the surrounding regional ecology and economy.

While the Great Lakes encompass much of Michigan's geography, they do not specifically delineate the boundary between the two peninsulas. The Detroit River, located to the south, separates Michigan from Canada and flows into Lake Erie, while Saginaw Bay is located to the east and is part of Lake Huron. None of these features create the direct separation that the Straits of Mackinac does between the Upper and Lower Peninsulas.