Early history The southern section of M-37 follows the path of an early
Indian trail that connected the St. Joseph Trail near
Kalamazoo and Battle Creek to the
Grand River Trail near present-day
Alto. These trails "were narrow and permitted only single-file travel." In the Grand Rapids area, Alpine Avenue was originally constructed as a
plank road. These roads were at least wide covered with wood planks thick. A portion of M-37 follows the route of the Muskegon, Grand Traverse and Northport State Road, which was later renamed the Newaygo and Northport State Road. The road was authorized by the state legislature in 1857, and it was intended to connect the settlements in
Muskegon and
Newaygo counties, which at the time were "most northerly on the south side of the 'Big Woods'", with the growing settlements around the
Grand Traverse Bay. Construction progressed slowly and was only opened through
Wexford County in 1863. and the bridge over the
Manistee River in 1864 at what is now
Sherman. The Custer Trail, named for General
George Armstrong Custer, was created in 1917 along a series of roads between Grand Rapids and
Ft. Wayne, Indiana that included the modern M-37. Custer commanded the Michigan Cavalry Bridge during the
Civil War, and he was wildly popular in the state after the war. The road that bears his name never achieved that level of popularity. By 1930, the name had already fallen out of use.
State highway era The
Michigan State Highway Department (MSHD) signed M-37 initially as part of the state trunkline highway system by July 1, 1919. This section of highway ran from Battle Creek to Grand Rapids, roughly along the modern routing. By 1929, the highway was extended north to
Peacock in
Lake County, replacing the contemporary
M-54 in the process. A group of local leaders formed an organization to lobby for the completion of the highway in 1928 when state efforts to do stalled. The Grand Rapids–Leelanau Association named their roadway the Paradise Trail and promoted it as an alternative to both US 31 and US 131. They convinced local land owners to donate land to build the road. Backers named the road for the "divine scenic and recreational delights" in the area. An unnumbered section of gravel highway was opened in 1937 west of
Cadillac; the roadway extended south from M-55 to the Wexford–Lake county line. Later, in 1940, the MSHD renumbered the north–south leg of
M-42 from Mesick north to Traverse City and Old Mission. As a result, M-37 was then a discontinuous highway with a gap between
M-63 in Peacock to M-115 at Mesick. The spur in Wexford County is shown after 1941 as an "earthen" highway, before disappearing from state maps completely in 1945. A section of M-37 through Newaygo County was renamed in 1945 for
Stevens T. Mason, the first governor of the State of Michigan. At the time,
Consumers Power Company recommended that all north–south roads in the county bear the name of a state governor as part of a plan to rename the major roads in the county. The company wanted to simplify directions for their employees looking for customers' homes in the area. In the middle of 1948, M-37 was extended to M-55 on a gravel highway that followed the previously unnumbered highway in Wexford County and a new roadway in Lake County. As a result, M-37 still had a gap, but only between M-55 and M-115. M-37 through the south side of the Grand Rapids area was realigned in late 1949 or early 1950. After the change, the highway follows Broadmoor Avenue to 28th Street and 28th Street west to its former routing along Kalamazoo Avenue. In 1953, this routing was shifted further when M-37 was rerouted to run north on East Beltline Avenue concurrent with US 131 and
M-21 to Cascade Road. There it turned west along Cascade Road and Fulton Street into downtown back to its existing alignment. During that same time frame, the gap in the routing between M-55 and Mesick was eliminated. The highway was moved to bypass Sparta, Kent City and Casnovia to the southwest in the 1962. Another change around the same time frame shifted M-37's routing through Grand Rapids again. This time, M-37 was rerouted to follow M-11/M-21 along 28th Street to the US 131 freeway north to I-96 and back to Alpine Avenue. The final Grand Rapids routing change was made in 1969 when M-37 was moved to its current course along East Beltline Avenue and I-96. This change resulted in a concurrency with the southernmost end of M-44 that was later removed in 1977 when M-44 was truncated northward. A proposed new routing near
Comstock Park in the 1970s would have removed M-37 from Alpine Avenue. The new highway, if built, would have run southeastward from the Alpine Avenue split to US 131 near 6 Mile Road. In 2008, the northernmost on the Old Mission Peninsula were designated what is now a Pure Michigan Scenic Byway by MDOT. In 2013, the hairpin curve on a hill north of
Mesick was straightened and the hill slightly leveled. To expand the blast radius for ammunitions testing at Fort Custer, MDOT rerouted the BL I-94/M-37 to run along the southern and eastern edges of the airport in Battle Creek instead of following roads on the opposite sides. This change was completed in 2015. MDOT and the Grand Traverse County Road Commission (GTCRC) announced in August 2019 that the GTCRC would take over ownership of M-37 on the Old Mission Peninsula north of Traverse City effective May 1, 2020. If the change were completed, MDOT would have removed M-37 from the US 31 concurrency through Traverse City, truncating the highway to terminate in Chums Corners. The City of Traverse City supported accepting jurisdiction of a section of M-37 north of US 31/M-72 to the city limits in February 2020. MDOT announced a public hearing for May 21, 2020, to take public comment on the transfer. Because only state trunkline highways are eligible for Pure Michigan Byway status and that section of M-37 has that status, the department is required to conduct at 30-day review of the transfer and removal of byway status. In May 2021, the department announced that it had cancelled plans to transfer M-37 to the local jurisdictions. ==Major intersections==