US 91 in Utah

US 91 in Utah



US 91
Get started Brigham City
End Lewiston
Length 54 mi
Length 87 km
Brigham City




According to foodezine, US 91 is a US Highway in the US state of Utah. The road forms a north-south route in the north of the state, from Interstate 15 in Brigham City through Logan to the border with Idaho. The route is 87 kilometers long.

Travel directions

US 91 at Richmond.

The road begins at its junction with Interstate 15, the highway from Salt Lake City and Ogden to Pocatello and Idaho Falls to the north. The road then has 2×2 lanes and after 1 kilometer the US 89 merges from Ogden, resulting in a double numbering until Logan, a distance of 55 kilometers. The road has 2×2 lanes for the entire route and goes from the valley of the Great Salt Lake to a second valley around the town of Logan. Logan is a regional town with a population of 43,000, and US 89 turns east here toward Jackson, Wyoming. US 91 then continues north as a 2×2 route to the Idaho border at Lewiston. US 91 in Idahothen continues to Pocatello.


The original US 91 (1926-1974).

Origin & route numbering

According to bittranslators, US 91 was introduced in 1926 and replaced State Highway 1. This indicates that this route was the most important in Utah at the time. State Highway 1 ran from the Arizona border at St. George through Salt Lake City to the Idaho border north of Logan. This route was approximately 690 kilometers long. However, it was not the longest road in Utah, the US 89 is longer.

The US 89 and US 91 have a strong relationship with each other. Both originally formed long north-south routes through central and southern Utah, separated by mountain ranges. US 89 was extended north into Idaho in the 1930s, creating a dual number with US 91 in the urbanized Wasatch Front, from Spanish Fork via Salt Lake City to Brigham City. North of Brigham City, US 89 followed a different route to Logan, but in 1954 this section was also double-numbered with US 91.

After the creation of the Interstate Highway system in 1956, Interstate 15 was built in the corridor of US 91, often directly over it. In the early 1970s, the construction of I-15 was so advanced that only a few parts of US 91 remained, so it was decided to scrap the southern part of US 91, since 1974 US 91 starts in Brigham City in northern Utah.

Asphalting of US 91

By the time US 91 was created in 1926, a significant portion of it was paved from Nephi in the south to Brigham City in the north, crossing Utah’s most populous region, the Wasatch Front. This paved section was already about 225 kilometers long, it was the only road in Utah that was already paved for more than a few kilometers. The remainder of US 91 was an improved gravel road. In the late 1920s, the northernmost section from Brigham City via Logan to the border with Idaho was also paved.

The asphalting of southern and central Utah mainly followed in the 1930s, in just a few years between 1930 and 1933 virtually the entire route was paved from the Arizona border to Nephi, a distance of 400 kilometers.

Replacement with I-15

From the 1930s through the 1960s-70s, US 91 was Utah’s main transportation route. Nearly all of the places of interest were along US 91. For this reason, Interstate 15 was chosen to largely follow the route of US 91, with two exceptions: in southern Utah, I-15 took a shorter route. Into Arizona, through the Virgin River Gorge, and into northern Utah, I-15 north of Brigham City follows a more westerly route to Idaho.

Between 1960 and 1975, large sections of I-15 were completed. By the mid-1970s, so few sections of US 91 were left that US 91 south of Brigham City was scrapped and the remaining sections were signposted as “temporary I-15.” South of St. George, I-15 took a more direct route to Arizona, due to the construction of I-15 through the Virgin River Gorge. The old route was a significantly longer route west from St. George and later south on what is now State Highway 8 and Old Highway 91. This is a 50-mile stretch and the longest intact portion of old US 91 in southern Utah.

Upgrades to US 91

Despite its length, former US 91 has been significantly upgraded in few places between the original surfacing in the 1930s and the construction of I-15. In the larger towns, the road is briefly a four-lane or five-lane road, in the Salt Lake City region the road is largely an urban arterial. The road forms the main street of Utah County and is a wide 7-lane city highway with center turn lane through and between Provo, Orem and American Fork. Also in the suburbs of Salt Lake City and in the city itself, the former US 91 is a major city highway with 5 to 7 lanes. The road runs through downtown Salt Lake City, partly on State Street, Salt Lake City’s main city thoroughfare.

The main 2×2 lane portion of US 91 that is non-urban lies between Brigham City and Logan in northern Utah. Logan is the largest city in Utah that is not on an Interstate Highway and US 91 is the main access road. This section was widened to 2×2 lanes in the 1950’s from Logan south to Brigham City. About 1957 the road was widened to 4 lanes on the south side of Logan, which was extended to Wellsville circa 1959. It was only much later that the mountain section between Brigham City and Wellsville was widened to 2×2 lanes, this happened in the mid-1990s.

The stretch from Logan to the Idaho border has also been widened to 4 lanes, partly as a 2×2 divided highway and partly as a 4 or 5-lane road with a center turn lane. In the early 1970s, the section between Logan and Smithfield was widened to 4 lanes. In about 2005, the northernmost section between Richmond and the Idaho border was widened to 4 lanes of traffic. Finally, in 2006, the section between Smithfield and Richmond was widened to 4 lanes.

Traffic intensities

The section between Brigham City and Logan has about 20,000 descending to 15,000 vehicles per day. Up to 40,000 vehicles pass through Logan, after which the intensities drop to 6,000 vehicles at the Idaho border.

US 91 in Utah