End of US highway 31

View a map showing this route.

Photo credits: Robert Halonen; Karin and Martin Karner; Robert Mortell; Alex Nitzman; Rich Rowland
Additional research: Christopher Bessert; Adam Froehlig

Approx. time period North terminus South terminus
1926-1940 (near St. Ignace, MI) Mobile, AL
1940-1960 Mackinaw City, MI Mobile, AL
1960-1991 (near Mackinaw City, MI) Mobile, AL
1991-present (near Mackinaw City, MI) Spanish Fort, AL

US 31 was one of the original 1926 routes. At the time, its northern terminus was at Rogers Park MI (that's basically at modern-day exit 352 on I-75, about 8 miles north of St. Ignace). Why did the route end at such an unlikely place? Well, US 2 didn't always serve St. Ignace. Originally it passed to the north of Brevort Lake to modern M-123, which it followed to Rogers Park:

Halonen, July 2002

Where M-123 ends today, US 2 continued north (left) to end at Sault Ste. Marie. Of course I-75 hadn't yet been built, so traffic actually followed Mackinac Trail, which is the T-intersection visible just beyond this interchange. So US 31's north beginning was to the right on Mackinac.

In about 1937, US 2 was changed such that it ran along the Lake Michigan shoreline between Brevort and St. Ignace, then north to connect with its original route at Rogers Park. However, US 31 was apparently co-signed with US 2 up to Rogers Park for another few years. It wasn't until 1940 that the US 31 designation was truncated to the ferry docks in Mackinaw City, where it ended along with US 23 and US 27 (you can view photos from there on this page).

This situation lasted around 20 years, until the Mackinac Bridge was completed in 1957. Then the north end of US 31 was rerouted away from the ferry docks, instead ending at the south landing of the Bridge. That was the case until about 1990, when US 31 was cut off to its modern terminus: just south of Mackinaw City, at I-75's interchange 336. In the photo below, we're on the ramp that merges with northbound I-75:

Ivy/Nitzman, 2009

That assembly used to be posted a little further ahead:

Rowland, June 2002

Mackinaw City is ahead about two miles. Heading the opposite direction (south on I-75), the north beginning of US 31 is heralded thus...

...and the first southbound marker looks like this:

Mortell, 2002

Mackinaw City is at the southern terminus of the Mackinac Bridge, which serves Michigan's Upper Peninsula. At the Bridge's dedication ceremony in 1958, each of Michigan's 83 counties chose a "Queen" to represent them; my very own mother was voted "Miss Missaukee County". You can view lots of old photos and news clippings here.

Throughout this time period, the south end of US 31 was in Mobile AL. Before I-65 was built, US 31 was the main north-south highway in Alabama, connecting Decatur, Birmingham, Montgomery, and Mobile. The two highways pretty much parallel each other throughout the state, but a notable divergence occurs at Bay Minette, north of Mobile. While I-65 crosses to the north of Mobile Bay and then heads south into Mobile, US 31 heads south first to Spanish Fort, and then west, parallel to I-10. Originally there was no US 98, but US 31 was co-signed with US 90 across Mobile Bay into its eponymous city. Adam writes:

"The original terminus in Mobile is impossible to place based on the early maps. I can conjecture four possibilities:

1) At today's US 90/US 98 intersection on the east side of the Bankhead Tunnel (approximately where old US 90 turned north towards the original Cochrane-Africatown bridge, before the Bankhead Tunnel opened in 1940);

2) At the St. Louis St/Joachim St intersection downtown (US 90 turned from north to east here);

3) At the Government St/Royal St intersection in downtown Mobile (this is where US 90 turned back towards the west);

4) At the Government St/Broad St intersection, which was also the original terminus of US 45 [photos on this page].

By 1949, you can rule out possibilities #2 and #3 above. Eventually (although exactly when is impossible to tell at this point), US 31's terminus was located at #1 above."

The photo below shows the scene from that approximate location as it appears today:

Nitzman, June 2003

That exit leads to the junction where US 31 once ended.

In 1991, the US 31 designation was truncated to its present-day terminus near Spanish Fort: on the east shore of Mobile Bay, at its junction with US 90/98, where those highways are routed onto Cochrane Bridge across Mobile Bay. In the photo below, you can see Mobile Bay straight ahead, to the west. Mobile itself is on the other side:

Nitzman, 1999

Within the next decade, those shields had been rearranged (and some of them replaced, as well):

Karners, Dec. 2009

If you were to turn left onto eastbound US 90/98, you'd actually be heading south for a time. You'd intersect I-10, and then US 90 and 98 would split. US 90 begins heading east, roughly along I-10. US 98 continues south for a few more miles, serving Daphne and Fairhope. But then it, too, turns back east, and it meets up with US 90 again in Pensacola FL. Looking north on westbound US 90/98, the south beginning of US 31 is signed thus:

Nitzman, June 2006

The assembly at far left is shown in the photo below:

Karners, Dec. 2009

That's from eastbound US 90/98, which turns south here. Straight ahead is the southernmost stretch of US 31 (which actually heads east for a few miles before turning to the north).