Historic US highway endpoints in Idaho Falls ID

Highway	Approx. time period
US 191	1926-1937
US 26	1951-1952
US 191	1972-1981
US 91	1980-2006

Photo credits: Chris Elbert

Today US 91 ends south of downtown Idaho Falls. But during much of the route's existence, it continued north through downtown, and on to Montana. The photo below is looking north on Yellowstone Avenue:

Elbert, Mar. 2006

That's now eastbound US 26 (which continues straight) and northbound Business Loop I-15 (which turns left at Broadway, the signal ahead). Originally US 91 turned left on Broadway as well, crossing the Snake River and then continuing north along its west bank. At the time, that direction was also westbound US 20, while eastbound was straight ahead. Also straight ahead was the south beginning of US 191. Just over a mile in that direction, we come to the junction pictured below:

Elbert, Mar. 2006

By this point, Yellowstone has become "Northgate Mile". Eastbound Business US 20 continues by angling to the left on Holmes Avenue, while US 26 continues straight via Northgate Mile. Today's BL 20 used to be mainline US 20/US 191, and for a very brief time during the early 1950's, straight ahead may have been the west beginning of US 26 (although it seems more likely that US 26 would've been co-signed with US 20 to the US 91 junction, which you've already seen above). The photo below is looking the opposite direction (southwest on Northgate Mile):

Elbert, Mar. 2006

This may have been a short-lived endpoint of US 26. Before that, US 20 and US 191 came in together from the right, and continued ahead. The US 191 designation would've ended at Broadway, where it junctioned with its "parent" route (US 91):

Elbert, Mar. 2006

Westbound US 20 continued to the right, and northbound US 91 was also that direction. Straight ahead was southbound US 91.

Later on, for about 30 years, US 191 was extended south into Utah. But then in 1972, it was truncated once again to Idaho Falls. It's possible that its endpoint was at one of the historic junctions shown above. But if that was ever the case, it was probably short-lived. By 1976 (maybe earlier), the US 20 freeway had been built along the north edge of town. It seems likely that US 191 traffic would've been directed to stay on that road, and that the designation would've ended at the junction with I-15 (interchange 119):

Elbert, Mar. 2006

Westbound US 20 continues by heading south on I-15 to the next exit (Broadway), but US 191 probably ended here until 1981, which is when it was completely removed from Idaho and instead extended through Wyoming, Utah, and Arizona. (By the way, the northbound control point is not "Roberts Butte" - rather, the reference is to Roberts ID and Butte MT.)

Right about the same time US 191 was moved out of Idaho, the designation of its "parent" (US 91) was truncated to the Idaho Falls area:

Elbert, Mar. 2006

That was looking north on Yellowstone Highway; the crossroad is 65th Street South. Downtown Idaho Falls is about four miles ahead; and about two miles to the left is I-15's interchange 113. Heading east from that interchange, the north beginning of US 91 was posted thus:

Elbert, Mar. 2006

That was from the perspective of eastbound US 26/northbound BL 15. To the right is a "ramp" to US 91, although the junction ahead is not grade-separated. And if you continued straight, you encountered a sign assembly with more complete information:

Elbert, Mar. 2006

The stop sign in the background is for traffic on the aforementioned ramp. There was a similar setup heading south on Yellowstone:

Elbert, Mar. 2006

Southbound drivers wanting to continue on westbound US 26/southbound BL 15 could use the ramp to the right, but directions were also provided at the 65th Street intersection itself...

Elbert, Mar. 2006

...although that should've been "South BL 15". If you continued straight ahead, you were on the north beginning of US 91, and you were soon greeted with the first confirming sign:

Elbert, 2003

Even traffic heading west on 65th Street (which is not a signed highway) was made aware of the routes signed through this intersection:

Elbert, Mar. 2006