Interstate 75 (I-75) is a part of the Interstate Highway System that runs from the Hialeah–Miami Lakes line to the Canadian border at Sault Ste. Marie, Michigan. I-75 enters the state from Ohio in the south, north of Toledo, and runs generally northward through Detroit, Flint, and Bay City, crosses the Mackinac Bridge and ends at the border in Sault Ste. Marie. The freeway runs for approximately 396 miles (637 km) on both of Michigan's major peninsulas. The landscapes traversed by I-75 include Southern Michigan farmland, northern forests, suburban bedroom communities, and the urban core of Detroit. The freeway also uses three of the state's monumental bridges to cross major bodies of water. There are four auxiliary Interstates in the state related to I-75, as well as nine current or former business routes, with either Business Loop I-75 or Business Spur I-75 designations.