Along its 355.2-mile-long (571.6 km) route, US 31 follows the Michigan section of the St. Joseph Valley Parkway as well as other freeways and divided highways northward to Ludington.

The first highways along the route of the modern US 31 corridor were the West Michigan Pike, an auto trail from 1913, and later a pair of state trunklines (the original M-11 and M-58) in 1919.

North of the Walton Road interchange, the freeway turns northwesterly to recross the St. Joseph River near Lake Chapin south of Berrien Springs.

As it approaches South Haven, the freeway passes near the Palisades Nuclear Generating Station and Van Buren State Park.

[3][5] North of Pentwater, US 31 crosses into Mason County and passes Bass Lake and the Ludington Pumped Storage Power Plant, which uses a reservoir next to the freeway to generate electricity.

As the trunkline rounds the northern shore of Manistee Lake, it passes the SS City of Milwaukee,[3][5] a car ferry preserved as a museum.

US 31 rounds the east side of the community's namesake body of water on Lake Street and exits town on Pleasanton Highway.

The highway runs north of the Cherry Capital Airport near the east arm as it angles southeasterly to Traverse City State Park.

East of the park, the trunkline exits suburban Traverse City and rounds the bay to run northward along its eastern shore.

[3][5] As US 31 curves around to the northeast and east in Charlevoix County, it follows a section of the Lake Michigan shoreline that is not considered to be part of any bay.

Their auto trail was marked by a series of concrete markers eight feet (2.4 m) tall along the 400-mile-long (640 km) roadway from the Indiana state line northward to Mackinaw City.

[23] By the end of the next year, the highway was extended across the Straits of Mackinac on the state car ferries to connect to US 2 in the Upper Peninsula north of St.

[32] The next year, the US 31 concurrency was removed from US 2 in the Upper Peninsula and the former highway no longer crossed the Straits of Mackinac, terminating instead in Mackinaw City.

[35] During World War II, a bypass of downtown South Haven was built; the former route of US 31 through the heart of the city was designated Bus.

[49][50] The MSHD petitioned federal highway officials to switch the Interstate designations west of Grand Rapids, reversing the I-96 and I-196 numbers to their current configurations.

[78] Since then, MDOT re-evaluated the St. Joseph Valley Parkway extension east of Benton Harbor, due to environmental, economic, and historical site issues.

[81] MDOT was given permission to modify the previously approved freeway to cross the Blue Creek on longer bridges; the USFWS also required that any construction be done from elevated platforms,[82] among other restrictions.

[80] In the interim, MDOT proceeded with construction of the southern portion of the last freeway segment, completing it northward from Berrien Springs to the Napier Avenue interchange in August 2003.

[83] The study recommended using a version of the alternate connection to avoid the Blue Creek Fen, both to save money and decrease impact to the Mitchell's satyr.

[85] MDOT did not include construction of the extension for this reason in the department's 2014–18 highway projects plan released in 2013, although most of the design work and land acquisition had been completed.

[86] Until the missing freeway segment was built, US 31 followed a stretch of Napier Avenue, which was upgraded in conjunction with the St. Joseph Valley Parkway opening to that point, westward to I-94.

[87] On December 6, 2018, MDOT announced that a $20 million discretionary grant had been received to complete the final phase of construction, building the last two miles (3.2 km) of freeway required to connect US 31 to I-94.

The project cost $121.5 million dollars and involved relocating the interchange with the eastern terminus of BL I-94 and reconstructing 3.5 miles (5.6 km) of I-94 in the area.

[92][c] By January 4, 2013, MDOT had completed work for this highway, including a bridge over North Cedar Drive, additional ramps at the I-96 and M-104 interchange, and reconstruction and widening of M-104 near I-96.

MDOT planned to build 1.4 miles (2.3 km) of the new highway starting in 2013, including the bridges over the Grand River and Little Robinson Creek.

The route of US 33 in the state, which at the time was concurrent with US 31, was dedicated as the Blue & Gray Trail in 1938 to honor veterans of the American Civil War.

[98] In 1917, the Upper Peninsula Development Bureau created a tourist route that is a predecessor of the modern Great Lakes Circle Tours (GLCT).

The concept did not last a year; the American entry into World War I and a lack of focus on a single route consigned the idea into obscurity.

MDOT and its counterparts in Wisconsin, Minnesota and Ontario created the GLCT scheme which includes the LMCT that follows US 31 from Lake Michigan Beach northward to Manistee and from Traverse City north to the terminus near Mackinaw City excluding locations where business loops run closer to the lake at South Haven, Muskegon, and Whitehall–Montague.

[103] The initial proposals had the byway continuing to Mackinaw City,[103] but as approved in 2016, it runs from New Buffalo on I-94 to Ludington, following US 31 except between business loops at South Haven, Muskegon, Whitehall–Montague and Pentwater.