Interstate 75 (I-75) is a part of the Interstate Highway System that runs north–south from Miami, Florida, to Sault Ste. Marie in the Upper Peninsula of the US state of Michigan. I-75 enters the state 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 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.

Sault Ste. Marie is a city in the Upper Peninsula of the U.S. state of Michigan. It is the county seat of Chippewa County and is the only city within the county. With a population of 13,337 at the 2020 census, it is the second-most populated city in the Upper Peninsula, behind Marquette. It is the primary city of the Sault Ste. Marie, MI Micropolitan Statistical Area, which encompasses all of Chippewa County and had a population of 36,785 at the 2020 census. Sault Ste. Marie was settled by mostly French colonists in 1668, making it the oldest city in Michigan.