End of US highway 91

View a map showing this route.

Photo credits: Chris Elbert; Dan Stober; "wbaron"; me

Approx. time period North terminus South terminus
1926-1938 Great Falls, MT Daggett, CA
1938-1947 Sweet Grass, MT Barstow, CA
1947-1965 Sweet Grass, MT Long Beach, CA
1965-1973 Sweet Grass, MT Barstow, CA
1973-1974 Sweet Grass, MT Primm, NV
1974-1980 Sweet Grass, MT Brigham City, UT
1980-2006 (near Idaho Falls, ID) Brigham City, UT
2006-present Idaho Falls, ID Brigham City, UT

US 91 is tragic figure in the story of US highways. It was an original 1926 route, running for over 1300 miles from US 66 in the Mohave Desert to Great Falls MT. Later both ends were extended, such that it ran from Long Beach CA all the way up to the Canada border at Sweetgrass MT. But the advent of the interstate highways pretty much spelled its doom: I-15 completely wiped it out north of Idaho Falls - and even for its first 100 or so miles south of Idaho Falls, it's a little-used road because it's still in the shadow of I-15. More at the end...

...but for now, on to the photos. These were taken at what I believe must've been the early termini of US 91 in California's Mohave Desert. Originally US 91 crossed the Mohave River at Daggett and ended at US 66 there. That location is shown below:

me, July 2004

That's looking south on Daggett-Yermo Road; I-40's interchange 7 is about a half-mile ahead. Old US 66 (now "National Trails Highway") is the crossroad running just south of the railroad, so US 91 would've ended at the intersection ahead. Below we're looking west on old US 66:

me, July 2004

The pavement was painted with "Historic US 66" shields. Barstow is about 8 miles ahead, and US 91 began to the right. That sign assembly is also visible in the photo below, which is looking north from old US 66:

me, July 2004

That was the south beginning of US 91; unfortunately I didn't have time to wait for the train to pass. The I-15 interchange is ahead about 2 miles.

Around 1938, the route of US 91 was changed slightly, such that it stayed on the north side of the river for another few miles, crossing at Barstow. It came into town on 1st Avenue, ending at US 66 (Main Street). Below is the modern signage posted at that intersection:

me, July 2004

That serves as a commentary on decommissioned routes in California: US 66 east of here was replaced by I-40, and US 66 to the west is now I-15. I-15 north used to be US 91, and CA hwy. 58 used to be US 466.

Below we're looking east on Main:

me, July 2004

The south beginning of US 91 was to the left.

In 1947 the US 91 designation was extended south from Barstow with US 66, ending at Long Beach (you can view photos from there on this page). The terminus remained there for nearly 20 years before it was truncated back to Barstow (presumably at the same location shown above). In 1973 California completely decommissioned US 91, so then the south end was on the Nevada line at Primm (if you'd like to see a photo from there, view my US 466 page). But then about one year later, both Nevada and Utah decommissioned hundreds of miles of US 91: everywhere it was concurrent with (or had effectively been replaced by) I-15. That shortened its southern extent to the modern terminus at Brigham City; the photo below shows where US 91 begins today:

me, Mar. 2001

That shot is from northbound I-15/I-84; the Wellsville Mountains are visible in the distance in that shot, and it's the Promontory Mountains shown in the photos below:

me, Mar. 2001

The shot above is looking west on 1100 South Street, or US 91. Brigham City (and the junction with US 89) is about 2 miles behind the camera. The US 91 designation ends at I-15/84's interchange 364 ahead, which is shown close-up below:

me, Mar. 2001

Further ahead, there's a mile 0 marker, which is shown in the photo below:

Stober

To the right is the southbound off-ramp; the southbound entrance ramp is to the left.

As I've said, the original north end of US 91 was in Great Falls (you can view photos from there on this page). In 1938 the designation was extended north to the Canada border. This portal is known as Sweet Grass in Montana, but in Alberta it's called Coutts. I was excited to find the photo below, because it shows the customs house before it was rebuilt:

wbaron, date unknown

That's looking south from Canada at the historic north beginning of US 91. That's also the north beginning of I-15, and presumably there were problems with heavy traffic that necessitated a new border station with much higher capacity. The photo below was taken heading the opposite direction (north):

Elbert, July 2008

That's the north end of I-15, and also what was once the north end of US 91. By 1980, I-15 north of Idaho Falls was almost entirely complete through Montana to the Canada line. I assume that's why, rather than co-signing US 91 with I-15, the decision was made to truncate it to its current northern terminus. For the next 25 years or so, the designation didn't quite make it even to Idaho Falls - rather, it ended a couple miles south of the city, where it junctioned with 65th Street South (which was the original routing of US 26 and Business Loop I-15... the historic Idaho Falls endpoint is among those shown on this page).

In 2006, Sunnyside Road was extended west via a new bridge over the Snake River, and on to I-15, where a new interchange was built. Sunnyside (the equivalent of 33rd Street South) is two miles north of 65th, and when the new road was complete, the US 26/Business 15 designations were changed to follow Sunnyside instead of 65th. So the US 91 designation had to be extended two miles north of its former terminus. Hopefully signage will be improved in the future, but here's all that was there in 2007:

Elbert, Aug. 2007

That's looking north on Yellowstone Highway at Sunnyside. US 91 ends here. Straight ahead is eastbound US 26 and northbound Business 15, while 26 west/15 south are to the left on Sunnyside. The photo below is looking east on Sunnyside:

Elbert, Aug. 2007

That's US 26/Business 15, which continue to the left on Yellowstone. To the right is the north beginning of US 91. The town of Shelley is about six miles that direction, but it isn't until way on the other side of Pocatello, at Virginia ID, that I-15 finally leaves this corridor, and US 91 gets to serve Preston ID and Logan UT on its own terms. That 60-mile portion is really its only remaining "necessary" segment, because south from Logan, US 91 is multiplexed with US 89 down to Brigham.

In its heyday before I-15, US 91 used to continue south from Brigham, together with US 89 along the Wasatch Front: through Ogden and Salt Lake, to the Provo area. There the two routes split to serve opposite sides of Utah's San Pitch, Pavant, and Tushar mountain ranges. US 91 went through Nephi, Fillmore, Beaver, Cedar City, and St. George: all on today's I-15. A relatively significant segment of old 91 (still drivable) took a different route than I-15 does between St. George and Littlefield AZ. Then on to Las Vegas NV, and into California: Barstow, San Bernardino, Riverside, and Long Beach.

The length of modern US 91 is only about one-tenth of its historical extent. And its branch highway, US 191, is now over ten times longer than US 91! If one were to try and drive historic US 91 from end to end, they'd be hounded by I-15 for nearly the entire journey. But then, several others of the truly great US highways have also been similarly "honored" with obsolesence due to the construction of parallel interstate highways.