US Highway 45 | ||||
|---|---|---|---|---|
 US 45 highlighted in red | ||||
| Route information | ||||
| Maintained by MDOT | ||||
| Length | 54.759 mi[1] (88.126 km) | |||
| Existed | c. 1935[2][3]–present | |||
| Major junctions | ||||
| South end |   US 45 / WIS 32 near Land O' Lakes, WI | |||
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| North end | Ontonagon & River streets in Ontonagon | |||
| Location | ||||
| Country | United States | |||
| State | Michigan | |||
| Counties | Gogebic, Ontonagon | |||
| Highway system | ||||
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US Highway 45 (US 45) is a part of the United States Numbered Highway System that runs from Mobile, Alabama, to the Upper Peninsula (UP) of the state of Michigan. The highway forms a part of the state trunkline highway system that is maintained by the Michigan Department of Transportation (MDOT). It enters the state from Wisconsin south of Watersmeet, ending at an intersection with Ontonagon Street in Ontonagon. In between, the roadway crosses the UP running for approximately 54+3⁄4 miles (88.1 km) through the Ottawa National Forest and parallel to the Ontonagon River.
The highway dates back to the 1930s in Michigan. At the time it was extended into the state, it replaced sections of M-26 and M-35. An eight-mile (13 km) segment was significantly reconstructed in the late 1950s, and an alignment change in the 1970s moved the routing of US 45 near Rockland before it was reversed soon afterwards. A segment of roadway that formerly carried US 45 is the site of the Paulding Light, a local phenomenon whose origins were scientifically described in 2010.