US Route 131 spends 99 percent of its time in Michigan, but it's a very important north-south highway in that state, positioned at a longitude one-quarter of the way east across Lower Michigan. That is to say, the path carved by US Route 131 roughly splits the western quarter of Lower Michigan from the eastern three-quarters. US Route 131 is the main north-south travel corridor through Grand Rapids and Kalamazoo, among other smaller towns. The length of US Route 131 outside of Michigan is less than a single mile, barely poking into Indiana to reach Interstates 80 and 90 (the Indiana Toll Road). From there, US Route 131 crosses northerly into Michigan to pass by White Pigeon, Constantine, and Three Rivers in southern Michigan. US Route 131 becomes a freeway alongside Kalamazoo, up to downtown Grand Rapids and beyond. The status of US Route 131 as a freeway continues north past Big Rapids and Cadillac to the town of Manton, just to the north of Cadillac. US Route 131 will exist as a two-lane rural highway from here onward to its northern terminus in Petoskey. It is here in Petoskey where US Route 131 connects to its namesake, US Route 31.
My photo of US Route 131 shows a northbound reassurance marker alongside the town of Constantine, in southern Michigan. Northbound travelers on the US highway will notice this sign as they pass or turn away from the intersection with Youngs Prairie Road. This photo was taken in March 2022, on the way home from a trip to Kalamazoo.