M-13 (Michigan highway)

M-13
} M-13 highlighted in red
Route information
Maintained by MDOT
Length	73.339 mi[1] (118.028 km)
Existed	c. 1932[2]–present
Tourist routes	Lake Huron Circle Tour
Major junctions
South end	I-69 near Lennon
Major intersections	M-57 near Montrose I-75 / US 23 near Saginaw BS I-75 / M-25 in Bay City
North end	US 23 near Standish
Location
Country	United States
State	Michigan
Counties	Shiawassee, Genesee, Saginaw. Bay, Arenac
Highway system
Michigan State Trunkline Highway System Interstate US State Byways
← M-12 → Conn. M-13

M-13 is a 73.339-mile (118.028 km) north–south state trunkline highway that runs through the Saginaw Bay region of the US state of Michigan. It runs from Interstate 69 (I-69) south of Lennon to US Highway 23 (US 23) near Standish. The southern section of the trunkline runs along a pair of county lines in a rural area dominated by farm fields. The highway directly connects the downtown areas of both Saginaw and Bay City. North of the latter city, the Lake Huron Circle Tour follows M-13 along the Saginaw Bay.

The original 1919 version of M-13 ran along the west side of the state, roughly replaced by what is now US 131 in 1926. The current highway was first designated by 1932 with the M-13 moniker. After a series of extensions in the 1930s, the highway ran from Lennon to Saginaw. Another set of expansions in the 1960s added roadways that previously carried US 23 all the way north to the Standish area. A related section of highway is numbered Connector M-13, a connector route that was once part of US 23 in the Kawkawlin area.