U.S. Route 26 (US 26) runs east–west across south central

Idaho Idaho ( ) is a state in the Pacific Northwest region of the Western United States. To the north, it shares a small portion of the Canada–United States border with the province of British Columbia. It borders the states of Montana and Wyomi ...

for . US 26 enters the state from

Oregon Oregon () is a state in the Pacific Northwest region of the Western United States. The Columbia River delineates much of Oregon's northern boundary with Washington, while the Snake River delineates much of its eastern boundary with Idaho. T ...

across the Snake River east of

Nyssa, Oregon Nyssa is a city in Malheur County, Oregon, United States. The population was 3,267 at the 2010 census. The city is located along the Snake River on the Idaho border, in the region of far eastern Oregon known as the " Treasure Valley". It is par ...

concurrent with US 20 and exits into

Wyoming Wyoming () is a state in the Mountain West subregion of the Western United States. It is bordered by Montana to the north and northwest, South Dakota and Nebraska to the east, Idaho to the west, Utah to the southwest, and Colorado to the s ...

northwest of

Alpine Alpine may refer to any mountainous region. It may also refer to: Places Europe * Alps, a European mountain range ** Alpine states, which overlap with the European range Australia * Alpine, New South Wales, a Northern Village * Alpine National Pa ...

. US 26 runs through the large population centers of

Boise Boise (, , ) is the capital and most populous city of the U.S. state of Idaho and is the county seat of Ada County. On the Boise River in southwestern Idaho, it is east of the Oregon border and north of the Nevada border. The downtown area' ...

and

Idaho Falls Idaho Falls ( Shoshoni: Dembimbosaage) is a city in and the county seat of Bonneville County, Idaho, United States. It is the state's largest city outside the Boise metropolitan area. As of the 2020 census, the population of Idaho Falls was 6 ...

, as well as the smaller communities of

Parma Parma (; egl, Pärma, ) is a city in the northern Italian region of Emilia-Romagna known for its architecture, music, art, prosciutto (ham), cheese and surrounding countryside. With a population of 198,292 inhabitants, Parma is the second mos ...

Notus In ancient Greek religion and myth, the Anemoi (Greek: , 'Winds') were wind gods who were each ascribed a cardinal direction from which their respective winds came (see Classical compass winds), and were each associated with various seasons ...

, Garden City, Shoshone, Richfield,

Carey Carey may refer to: Names * Carey (given name), a given name * Carey (surname), a surname ** List of people with surname Carey Places Canada * Carey Group, British Columbia; in the Pacific * Carey Island (Nunavut) in James Bay United Kingdom ...

, Arco, Blackfoot, Swan Valley, and

Irwin Irwin may refer to: Places ;United States * Irwin, California * Irwin, Idaho * Irwin, Illinois * Irwin, Iowa * Irwin, Nebraska * Irwin, Ohio * Irwin, Pennsylvania * Irwin, South Carolina * Irwin County, Georgia * Irwin Township, Venango County ...

. For a vast majority of its route, US 26 is two-lane and rural, with the exception of portions in and around major towns and cities. It does have significant four-lane segments within the Boise metropolitan area and east of

. Despite its extensive length, US 26 has many hundreds of miles that run concurrently with other highways. In fact, its first in the state consists of concurrencies with any one of five different highways, principally US 20 and

I-84 Interstate 84 may refer to: * Interstate 84 (Oregon–Utah), passing through Idaho, formerly known as Interstate 80N * Interstate 84 (Pennsylvania–Massachusetts) Interstate 84 (I-84) is an Interstate Highway in the Northeaster ...

. It has additional lengthy concurrencies with US 93, US 20 again, and I-15. US 26 does have one business route in the state of Idaho, which runs through the small community of Ririe northeast of Idaho Falls.

Route description

Oregon state line to Downtown Boise

After crossing the Snake River at the Oregon state line, US 26 and US 20 make a curve towards US 95. At that point, both routes travel south along US 95. The three routes then travel south and then curves southeast in Parma. Then, US 95 branches southward while the rest continues southeast. Both US 26 and US 20 pass through Notus before meeting I-84/US 30. At this point, the four routes meet I-84 BL and then 10th Avenue before US 20 and US 26 travel east on Franklin Road; all of the exits are in Caldwell. As the two routes approach

, they intersect three state highways: SH-16, SH-55 in Eagle–Boise line, and SH-44 in Garden City. In Boise, as US 26 and US 20 merge eastward onto I-184, the interstate designation ends there but the freeway ends in about . Just after the freeway crosses the Boise River, both routes traveling eastbound serve River Street and

Bogus Basin Bogus Basin Mountain Recreation Area is a ski area in Boise County, Idaho, north-northeast of the city of Boise. Bogus is operated by the Bogus Basin Recreation Association, a non-profit organization, on private and leased land in the Boise Nat ...

. After this, the freeway approaches a curve and then becomes an at-grade one-way pair.

Downtown Boise to Blackfoot

As both routes exit downtown, they turn south and become a two-way street. Also, the two routes cross the Boise River for the second time. After that, they run along the eastern edge of the

Boise State University Boise State University (BSU) is a Public university, public research university in Boise, Idaho. Founded in 1932 by the Episcopal Church (United States), Episcopal Church, it became an independent junior college in 1934 and has been awarding ...

. As they approach

Boise Airport Boise Airport (Boise Air Terminal or Gowen Field) is a joint civil-military airport in the western United States, south of downtown Boise in Ada County, Idaho. The airport is operated by the city of Boise Department of Aviation and is oversee ...

, they then turn east onto I-84/US 30 again. This time, US 26 runs concurrently with I-84 for about . Along the way, the freeway serves several state highways, I-84 Business Loops, and local roads in different locations. At one point east of Mountain Home, US 20 leaves the freeway and travels northeastward. As the freeway reaches Bliss, US 30, along with I-84 BL, leaves the freeway as Thousand Springs Scenic Byway. At the next exit, US 26 leaves the freeway. US 26 went on to serve a handful of state highways in Gooding and Shoshone. Also in Shoshone, the route begins to run concurrently with US 93. Both routes then serve Richfield. In

, they begin to run concurrently with US 20. For US 26, this is the second time in Idaho. The three routes serve

Craters of the Moon National Monument and Preserve Craters of the Moon National Monument and Preserve is a U.S. national monument and national preserve in the Snake River Plain in central Idaho. It is along US 20 ( concurrent with US 93 and US 26), between the small towns of Arco and Carey, a ...

and Blizzard Mountain Ski Area. In Arco, US 93 branches northwestward. The rest continues eastward through Butte City and serving SH-33. Just southeast of the base of Idaho National Laboratory, US 26 branches southeast towards Blackfoot while US 20 continues east. As US 26 approaches Blackfoot, the route intersects SH-39 and then crosses over the same Snake River. Shortly after that, it turns northeast onto I-15 while the road continues as I-15 BL.

Blackfoot to Wyoming state line

At this point, US 26 begins to run concurrently with I-15 for the next . All of the interchanges within this concurrency lead to local roads. As the freeway enters

, US 26 leaves the freeway and turns east along I-15 BL. Both routes then cross the Snake River (third time for US 26) and then intersect the northern terminus of US 91. At this point, both travel north toward downtown Idaho Falls. In downtown, I-15 BL branches westward towards I-15/US 20. Continuing northeast, US 26 intersects several more routes: SH-43 in Beachs Corner, US 26 Bus. (twice) near Ririe, and SH-31 in Swan Valley. Continuing eastward, US 26 travels along the bank of Snake River and then enters Wyoming.

History

When US 26 was initially designated in the state in 1951, it ran only as far west as

. The next year, it was extended into

Major intersections

Ririe business route

U.S. Route 26 Business (US 26 Bus.) is a business route in and around the small town of Ririe northeast of

. It connects US 26 to the community as well as SH-48.

References

{{reflist Idaho Transportation in Canyon County, Idaho Transportation in Ada County, Idaho Transportation in Elmore County, Idaho Transportation in Gooding County, Idaho Transportation in Lincoln County, Idaho Transportation in Blaine County, Idaho Transportation in Butte County, Idaho Transportation in Bingham County, Idaho Transportation in Bonneville County, Idaho 26