M-91 (Michigan highway)

M-91
M-91 highlighted in red
Route information
Maintained by MDOT
Length	24.464 mi[1] (39.371 km)
Existed	1942[2]–present
Major junctions
South end	M-44 near Belding
Major intersections	M-57 at Greenville
North end	M-46 at Lakeview
Location
Country	United States
State	Michigan
Counties	Ionia, Montcalm
Highway system
Michigan State Trunkline Highway System Interstate US State Byways
← M-90 → M-92

M-91 is a largely north–south state trunkline highway in the Lower Peninsula of the US state of Michigan. It runs from Belding to south of Lakeview. Its 24-mile (39 km) length exists entirely within Ionia and Montcalm counties. It is all undivided surface route. Aside from the two Michigan state highways that are its termini, it has only one other intersection with any Michigan state highway, and that is with M-57 in Greenville.

M-91 was formed when M-66 was rerouted in the 1940s. At the time, the highway continued south to Lowell, but subsequent transfers or roadway sections have truncated the route to its present form. For a time period in the 1980s, M-91 was even a discontinuous highway when a section in the middle was transferred to county control before the southernmost section was transferred.