End of historic US highway 312

Note: since I don't have access to a comprehensive collection of historical road atlases, much of the info below is based on the research of Robert Droz; click here to view his site. Photo credits: Chris Elbert; me

It's impossible to tell the complete story of US 312 without involving its parent (US 12) and sibling (US 212). The east end of US 12 has been in Detroit since the beginning in 1926. At that time, the west end was at US 10 in Miles City MT. But in 1939, US 12 was extended west: co-signed with US 10 through Billings to Laurel MT, and then southwest via present-day US 212, ending at the NE entrance to Yellowstone National Park. Meanwhile, US 212 was extended westward to Broadus MT, but then went north via today's MT hwy. 59, ending at Miles City.

Twenty years later (1959), the US 12 designation was changed to its modern configuration: it split off from US 10 at Forsyth (between Miles City and Billings) to follow its present route through Helena to Missoula. That change necessitated the birth of US 312: it followed the former route of US 12 from Forsyth through Billings to NE Yellowstone (view photos from there on this page). The shot below is looking west on Front Street in Forsyth:

Google Maps Street View, 2008

That was westbound US 12, which originally continued straight ahead. When it was rerouted in 1959, US 12 continued to the right (over the railroad bridge), and then straight ahead became the east beginning of US 312.

Three years later (1962) brought another change: instead of ending at Miles City, US 212 went west from Broadus along its present path, ending as it does today at Yellowstone. So the west end of US 312 was truncated back to Billings, but the east end of the designation was extended: co-signed with US 12 to Miles City, then south along US 212's former route to end at US 212 in Broadus. That's how things were for nearly 20 years, until US 312's decommissioning in 1981. The photo below is looking south on MT hwy. 59:

Elbert, July 2005

Today MT 59 is co-signed with US 212 east from here to Broadus (about 3 miles) and then another 4 miles east before heading southward into Wyoming on its own. But that used to be the east end of US 312. Below we're looking east on US 212:

Elbert, July 2005

Broadus is ahead; to the left used to be the east beginning of US 312. Below the view is from the opposite direction (west on US 212):

Elbert, July 2005

US 312 began to the right, on its way to Billings, which was where its western terminus was situated for most of its existence. The photo below is looking south on Main Street, or US 87:

me, Mar. 2001

US 312 used to be co-signed with US 87 to this point (1st Avenue North). 1st was originally US 10, and later US 12. Now it's nothing but Business Loop I-90. The shot below is looking east on 1st:

me, Mar. 2001

To the left was once the west beginning of US 312. Heading that direction, it wasn't far before US 312 split off from US 87. To this day, locals still refer to that road as "Old Highway 312".