I took this picture from the path that leads from the visitor's center at Fort Michilimackinac to the fort itself. It shows the Mackinac Bridge from below. That's Lake Michigan to the left of the bridge (as the sign indicates). Lake Huron is to the right. The area is known as the Straits of Mackinac. Click to enlarge. By the way, "Michilimackinac" is pronounced "Mah-SHIL-e-MACK-in-AW."
