US Highways

Since US Highways tend to be long, I've decided to cover them in segments. Below is a list of those segments (which will be linked to blog posts once I've written about them), and a brief history of the US highways in the state.

US 6:

  • Nevada-Delta
  • Delta-Santaquin
  • Santaquin-Moark Jct.
  • Moark Jct.-Thistle
  • Moark Jct.-Castle Gate
  • Castle Gate-Green River
  • Green River-Colorado

US 30S (old):
  • Idaho-Tremonton
  • Tremonton-Brigham City
  • Brigham City-Ogden
  • Ogden-Wyoming

US 40:
  • Nevada-Lake Point
  • Salt Lake City
  • Salt Lake City-Park City
  • Park City-Heber City
  • Heber City-Duchesne
  • Duchesne-Vernal
  • Vernal-Colorado
  • Alternate: Salt Lake City
  • Alternate: Park City

US 50:
  • Nevada-Delta
  • Delta-Holden
  • Holden-Scipio
  • Scipio-Salina
  • Salina-Green River
  • Green River-Colorado
  • Alternate: Salt Lake City

US 89:
  • Arizona-Kanab
  • Kanab-Sevier
  • Sevier-Salina
  • Salina-Thistle
  • Thistle-Moark Jct
  • Moark Jct-Lehi
  • Lehi-Draper
  • Salt Lake Valley
  • Salt Lake City-Bountiful
  • Bountiful-Farmington
  • Farmington-Ogden
  • Ogden-Brigham City
  • Brigham City-Logan
  • Logan-Idaho

US 89A:
  • Arizona-Kanab

US 91:

US 160:

US 163:
US 189:
  • Alternate: Kamas

US 189 (old):
US 191:

US 191 (old):
  • Brigham City-Tremonton
  • Tremonton-Idaho

US 450:

US 491:
US 530:
  • Kimball Jct-Echo

US 666:


What follows is a general outline of how the US Highway network in Utah has changed through the years. Minor realignments and short alternate routes in cities generally are not covered here.

As is well known in most road enthusiast circles, the original US highway system was proposed by the American Association of State Highway Official (AASHO) in 1925. In Utah, this system included the following routes:

  • US 30, from US 91 in Salt Lake City to Wyoming via Kimball Junction and Echo
  • US 40, from Nevada to Colorado via Wendover, Salt Lake City, Provo, Duchesne, and Vernal
  • US 50, from Nevada to Colorado via Delta, Santaquin, Spanish Fork, Price, Green River, and Valley City
  • US 89, from Arizona to US 91 in Spanish Fork via Kanab, Richfield, Manti, and Thistle
  • US 91, from Arizona to Idaho via Shivwits, St George, Cedar City, Provo, Salt Lake City, Layton, Ogden, Brigham City, Logan, and Smithfield
  • US 191, from US 91 in Brigham City to Idaho via Tremonton and Snowville
  • US 450, from US 50 at Valley City to Colorado via Moab and Monticello
  • US 630, from US 91 in Ogden to US 30 near Echo via Morgan
Wikipedia user SPUI made a map of this plan; below is a portion of that map including Utah:

Source: Wikimedia Commons (by user SPUI).

However, some substantial alterations to that system occurred before the final plan was approved in 1926. One such change was made to US 50, which was given a gap between Ely, NV and Thistle, UT - because the originally proposed route through the Utah west desert was of such poor quality that it was deemed to be nearly impassable and not fitting of a major cross-country highway.

Only three routes from the 1925 proposal were unchanged in the 1926 plan: US 89, 91, and 450. Other than those three and US 50, all US routes in the state were affected in some way by a major dispute between Utah/Wyoming and Idaho/Oregon over the routing of US 30, which I will almost certainly write about in a future blog post. The final outcome of that in Utah was as follows:
  • US 30S, from Idaho to Wyoming via Snowville, Tremonton, Brigham City, Ogden, and Echo
  • US 40, from Nevada to Colorado via Wendover, Salt Lake City, Heber City, Duchesne, and Vernal
  • US 530, from US 40 at Kimball Junction to US 30S near Echo

Rand McNally's 1927 Utah map showed those changes, though it did still erroneously include US 50 through western Utah.

Rand McNally (Utah), 1927.

US 50 was eventually connected between Ely and Thistle, but that connection did not go through Delta as originally planned. Instead, it ran through Wendover and Salt Lake City, mostly along concurrencies with US 40 and US 91.

A new US 189 was created around 1930, but this was completely unrelated to the US 189 that exists today. It ran from US 91 in Nephi to US 89 at Pigeon Hollow Junction.

In 1937, US 6 was extended across much of the US. In Utah, the new US 6 ran concurrent with US 50 east of Moark Junction. West of there, it followed the originally planned US 50 alignment across the west desert through Delta towards Ely. The same year, US 191 was extended south from Idaho Falls, ID to Tremonton via Plymouth and Riverside. It would be extended further to US 91 at Brigham City in 1946.

The late 1930s featured a planned extension of US 89, along with a dispute between Utah/Idaho and Wyoming on its routing. That will also be detailed further in a future post, but the outcome was as follows:

  • US 89 extended north to Idaho, mostly along a concurrency with US 91. The new extension left 91 twice: once between Farmington and Ogden, and again north of Logan.
  • The original US 189 was decommissioned.
  • A new US 189 was created, running from Provo to Wyoming via Heber City. Concurrent with US 40 from Heber to the Park City area, and with US 30S from Echo to Wyoming. US 530 was absorbed by this extension.
US 450 was renumbered as a western extension of US 160 in 1939.

For a time in the 1940s and 1950s, US 89 diverged again from US 91 between Brigham City and Logan, avoiding Sardine Canyon and entering the Cache Valley through Collinston and Petersboro. (this is now SR 38 and SR 30). US 89 was moved back to Sardine in 1953.

In 1952, a new alignment had been built across the Utah west desert between Nevada and Delta, and US 6 was moved to that. That was also enough to finally move US 50 to its originally proposed route through Delta and Santaquin; the old route through Salt Lake became Alternate 50.

As the interstates began to be built, a handful of US route decommissionings and truncations began. One of the first was US 191, which was truncated back to Tremonton in 1962.

In 1970, a major realignment (which will probably also get its own post eventually) occurred in southeastern Utah, and the road from Monument Valley to Monticello was added to the US Highway system. As it relates to the US route designations, the end result of this was as follows:
  • US 160 decommissioned.
  • US 163 created, from Arizona to Crescent Junction (US 6/50) via Mexican Hat, Bluff, and Monticello
  • US 666 extended northwest from Cortez, CO, terminating at US 163 in Monticello  

The early 1970s saw a whole series of US route-related eliminations and truncations. US 191 was removed from the state in 1972, US 30S was decommissioned the same year, US 91 was truncated to Brigham City in 1974, and US 40 was truncated to Silver Creek Jct in 1975.

In 1976, US 50 was moved once more, this time to its modern routing from Delta through Scipio and Salina and eastward on I-70. However, US 6 was not moved, and still remains on more or less its original routing.

1982 saw a major extension of US 191 back through Utah, but this time in the eastern part of the state. The new 191 added mileage to the US system between Arizona and Bluff, between Castle Gate and Duchesne, and from Vernal north to Wyoming. Those new segments were connected by several new concurrencies: 191 overlapped with US 163 from Bluff to Crescent Jct, US 6 from Crescent Jct to Castle Gate, and US 40 from Duchesne to Vernal.

US 163 was soon no longer signed north of Bluff, but Utah never officially asked AASHTO to decommission that portion of US 163 until 2008. This was done, but UDOT internal documentation still considers 163 to exist all the way up to I-70.

Finally, as many readers of this blog may know, US 666 was renumbered to US 491. Contrary to popular belief, this was not done because of superstition, but primarily because sign theft was so prolific it was impossible to keep the signs up for essential navigation purposes.

1 comment:

  1. "sign theft was so prolific it was impossible to keep the signs up for essential navigation purposes'
    :) Awesome story!