Michigan Highway 13 runs north-south from Lennon to Standish in central Michigan. The northern half runs along the western side of Saginaw Bay. Exit 123 from Interstate 69 is home to the southern end of Michigan Highway 13. From there, Michigan Highway 13 heads north through Lennon to Saginaw. In Saginaw, the route follows the east bank of the Saginaw River. It follows the river right under Interstate 75 so that it reaches the eastern side of that freeway. Michigan Highway 13's next stop is Bay City, and just north of Bay City, a connecting spur marked as a branch of Michigan Highway 13 connects to Interstate 75. Beyond there, it's sandwiched between Interstate 75 and Saginaw Bay. This stretch is the final stretch, and Michigan Highway 13 ends as the northbound alignment is stolen by US Route 23. US Route 23 jogs eastward from Interstate 75 just to steal Michigan Highway 13's thunder, and Michigan Highway 13 ends here, just south of Standish.
My photo of Michigan Highway 13 comes from its junction with Michigan Highway 247, north of Bay City. Michigan Highway 247 is the spur route to Bay City State Park. The photo shows a northbound reassurance marker for travelers leaving the junction with Michigan Highway 247. This photo was taken during a trip around central and south-central Michigan in March 2019.