M-43 (Michigan highway)

M-43
M-43 highlighted in red
Route information
Maintained by MDOT
Length	144.835 mi[1] (233.089 km)
Existed	1919–present
Major junctions
West end	BL I-196 in South Haven
Major intersections	M-40 near Gobles US 131 near Kalamazoo M-89 from Plainwell to Richland M-37 in Hastings M-50 / M-66 near Woodland I-96 / I-69 near Lansing US 127 near East Lansing
East end	I-96 near Webberville
Location
Country	United States
State	Michigan
Counties	Van Buren, Kalamazoo, Allegan, Barry, Eaton, Ingham
Highway system
Michigan State Trunkline Highway System Interstate US State Byways
← M-42 → M-44

M-43 is a state trunkline highway in the southwestern and central parts of the US state of Michigan. The highway runs from South Haven to Webberville along an indirect path through both rural areas and larger cities. The trunkline follows five overall segments: a southeasterly track from South Haven to Oshtemo Township (just west of Kalamazoo), a northerly path to Plainwell, a southeasterly route to Richland, a northeasterly course to the Hastings area and an easterly route through the Lansing area.

The M-43 designation dates back to at least July 1, 1919, when it was used on a series of roadways running between Kalamazoo and St. Charles. Its northern- and easternmost sections were transferred to other highways in the 1930s. Additions to M-43 extended it to its current termini. Several sections of the highway were realigned during its history, one of these changes led to the creation of a business loop in Grand Ledge. Another former segment of the trunkline in the Lansing area has been renumbered M-143. In January 2019, the highway was rerouted north to bypass downtown Kalamazoo, where it had historically formed a high traffic trunkline through the city. The former segment between Kalamazoo and Richland was renumbered M-343.