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 on both of Michigan's 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 (BL I-75) or Business Spur I-75 (BS I-75) designations.