M-123 (Michigan highway)
| Route information | ||||
|---|---|---|---|---|
| Maintained by MDOT | ||||
| Length | 96.071 mi (154.611 km) | |||
| Existed | 1936–present | |||
| Tourist routes | Lake Superior Circle Tour Tahquamenon Scenic Heritage Route | |||
| Major junctions | ||||
| South end | I-75 near St. Ignace | |||
| North end | M-28 near Newberry | |||
| Location | ||||
| Country | United States | |||
| State | Michigan | |||
| Counties | Mackinac, Chippewa, Luce | |||
| Highway system | ||||
| ||||
M-123 is a state trunkline highway in the eastern Upper Peninsula of the US state of Michigan. It is one of only a few highways in Michigan that curve around and form a U-shape. In fact, M-123 has three intersections with only two state trunklines; it meets M-28 twice as a result of its U-shaped routing. M-123 also has a rare signed concurrency with a County-Designated Highway in Michigan; in Trout Lake, there is a concurrency with H-40. All of M-123 north of M-28 is a Scenic Heritage Route within the Michigan Heritage Route system.
The highway was first designated before 1936 along a section of its current routing. Sections added since then encompass segments formerly belonging to US Highway 2 (US 2) and M-48. The last changes came to the highway in 1962 and 1963, when the northern end was extended and the southern end was truncated slightly.