Interstate 75 (I-75) is a part of the Interstate Highway System that runs from Miami, Florida, to Sault Ste. Marie in the Upper Peninsula of Michigan. I-75 enters Michigan from Ohio in the south, north of Toledo and runs generally northward through Detroit, Pontiac and Bay City, crosses the Mackinac Bridge, and ends at the Canadian border in Sault Ste. Marie. The freeway runs for approximately 396 miles (637 km) on both of Michigan's peninsulas.