Interstate 84 (I-84) is an

Interstate Highway The Dwight D. Eisenhower National System of Interstate and Defense Highways, commonly known as the Interstate Highway System, or the Eisenhower Interstate System, is a network of controlled-access highways that forms part of the National Hi ...

in the

northwestern United States The Northwestern United States, also known as the American Northwest or simply the Northwest, is an informal geographic region of the United States. The region consistently includes the states of Oregon, Washington, Idaho, Montana and Wyoming ...

. The highway runs almost 770 miles (1239 km) from

Portland, Oregon Portland ( ) is the List of cities in Oregon, most populous city in the U.S. state of Oregon, located in the Pacific Northwest region. Situated close to northwest Oregon at the confluence of the Willamette River, Willamette and Columbia River, ...

, to a junction with

I-80 Interstate 80 (I-80) is an east–west transcontinental freeway that crosses the United States from San Francisco, California, to Teaneck, New Jersey, in the New York metropolitan area. The highway was designated in 1956 as one of the ori ...

near Echo, Utah. The highway serves and connects Portland,

Boise Boise ( ) is the capital and most populous city of the U.S. state of Idaho. As of the 2020 census, there were 235,685 people residing in the city. Located on the Boise River in southwestern Idaho, it is east of the Oregon border and nor ...

, and

Ogden, Utah Ogden ( ) is a city in and the county seat of Weber County, Utah, Weber County, Utah, United States, approximately east of the Great Salt Lake and north of Salt Lake City. The population was 87,321 in 2020, according to the United States Census ...

. With connections to other highways, I-84 connects these cities to points east and also serves as part of a corridor between

Seattle Seattle ( ) is the most populous city in the U.S. state of Washington and in the Pacific Northwest region of North America. With a population of 780,995 in 2024, it is the 18th-most populous city in the United States. The city is the cou ...

and

Salt Lake City Salt Lake City, often shortened to Salt Lake or SLC, is the capital and most populous city of the U.S. state of Utah. It is the county seat of Salt Lake County, the most populous county in the state. The city is the core of the Salt Lake Ci ...

. The sections running through Oregon and Idaho are also known as the Vietnam Veterans Memorial Highway."" The highway originally served as a fork of I-80 to serve the

Pacific Northwest The Pacific Northwest (PNW; ) is a geographic region in Western North America bounded by its coastal waters of the Pacific Ocean to the west and, loosely, by the Rocky Mountains to the east. Though no official boundary exists, the most common ...

, and was originally numbered Interstate 80N. It was generally built along the corridor of U.S. Route 30 (US 30) and US 30S, which themselves largely followed the

Oregon Trail The Oregon Trail was a east–west, large-wheeled wagon route and Westward Expansion Trails, emigrant trail in North America that connected the Missouri River to valleys in Oregon Territory. The eastern part of the Oregon Trail crossed what ...

; the US 30S designation was decommissioned in the 1970s after the freeway replacement was mostly complete. The highway was signed with the I-84 designation in 1980, when a 1977 change in guidelines took effect that discouraged highway numbers with directional suffixes. The renumbering resulted in two highways being numbered I-84, with the other located in the

Northeastern United States The Northeastern United States (also referred to as the Northeast, the East Coast, or the American Northeast) is List of regions of the United States, census regions United States Census Bureau. Located on the East Coast of the United States, ...

Route description

, - , , , - , , , - , , , - , Total ,

Oregon

In the

Portland metropolitan area The Portland metropolitan area is a metropolitan area, metro area with its urban area, core in the U.S. states of Oregon and Washington (state), Washington. It has 5 principal cities, the largest being Portland, Oregon. The U.S. Office of Man ...

, I-84 is sometimes referred to as the "Banfield Freeway" or simply "the Banfield", although the official name is the Banfield Expressway. This freeway is named after Thomas H. "Harry" Banfield (1885–1950), the chairman of the Oregon Transportation Commission from 1943 to 1950. As I-84 heads east, it also follows US 30 in a majority of I-84 from Portland, Oregon, to near Rupert, Idaho, with splits being variant in Oregon and Idaho, but before leaving Portland, there is a junction with I-205, along with cities Gresham, Fairview, Wood Village and Troutdale. I-84 ColumbiaR

Immediately after leaving Troutdale, I-84 and US 30 runs east along the south bank of the

Columbia River The Columbia River (Upper Chinook language, Upper Chinook: ' or '; Sahaptin language, Sahaptin: ''Nch’i-Wàna'' or ''Nchi wana''; Sinixt dialect'' '') is the largest river in the Pacific Northwest region of North America. The river headwater ...

(and the northern Oregon border, as well) for nearly with the first 80 miles being in the Columbia River Gorge National Scenic Area, running from Troutdale to the Deschutes River, passing through the cities of Hood River and The Dalles in the Scenic Area. It also passes through Biggs Junction, Rufus, Arlington, and Boardman outside of the Scenic Area before heading southeast to the junction with southern end of I-82 immediately southeast of the Umatilla Chemical Depot near Hermiston. From the junction it continues southeast on to Pendleton. East of Pendleton, I-84 climbs Emigrant Hill, a 6% grade, into the Blue Mountains. The westbound lanes switchback twice on its descent into Pendleton. Eastbound lanes feature the tightest curves allowed on the Interstate Highway system, even though those curves are on the uphill (eastbound) direction. This grade is also well known because of the distance between eastbound and westbound lanes, nearly between the opposite directions of travel at some points. The road summits at

above sea level Height above mean sea level is a measure of a location's vertical distance (height, elevation or altitude) in reference to a vertical datum based on a historic mean sea level. In geodesy, it is formalized as orthometric height. The zero level ...

before descending to the Grand Ronde River and La Grande. It passes by North Powder and Baker City and through the Burnt River canyon. Around Huntington, it crosses into the

Mountain Time Zone The Mountain Time Zone of North America keeps time by subtracting seven hours from Coordinated Universal Time (UTC) when standard time ( UTC−07:00) is in effect, and by subtracting six hours during daylight saving time ( UTC−06:00). The ...

then briefly follows the southwest bank of the

Snake River The Snake River is a major river in the interior Pacific Northwest region of the United States. About long, it is the largest tributary of the Columbia River, which is the largest North American river that empties into the Pacific Ocean. Begin ...

( Brownlee Reservoir), then continues to

Ontario Ontario is the southernmost Provinces and territories of Canada, province of Canada. Located in Central Canada, Ontario is the Population of Canada by province and territory, country's most populous province. As of the 2021 Canadian census, it ...

before crossing the Snake River into

Idaho Idaho ( ) is a landlocked U.S. state, state in the Pacific Northwest and Mountain states, Mountain West subregions of the Western United States. It borders Montana and Wyoming to the east, Nevada and Utah to the south, and Washington (state), ...

. On March 1, 2016, the speed limit from The Dalles to Ontario was raised to , while the truck speed was raised to .

Idaho

I-84 enters Idaho by crossing the

, Oregon. From there, it continues on to the major cities of the

Treasure Valley The Treasure Valley is a valley in the western United States, primarily in southwestern Idaho, where the Payette, Boise, Weiser, Malheur, and Owyhee rivers drain into the Snake River. It includes all the lowland areas from Vale in rural east ...

(or

Boise metropolitan area The Boise, Idaho Metropolitan Statistical Area (MSA) (commonly known as the Boise Metropolitan Area or the Treasure Valley) is an area that encompasses Ada County, Idaho, Ada, Boise County, Idaho, Boise, Canyon County, Idaho, Canyon, Gem County, ...

) including Caldwell, Nampa, Meridian, and

(where I-184 connects travelers to downtown). From Boise, I-84 continues southeast passing near several small cities ( Mountain Home, Glenns Ferry, and

Jerome Jerome (; ; ; – 30 September 420), also known as Jerome of Stridon, was an early Christian presbyter, priest, Confessor of the Faith, confessor, theologian, translator, and historian; he is commonly known as Saint Jerome. He is best known ...

) on its way to Twin Falls. Just east of Jerome, I-84 passes within of Twin Falls, but does not cross the Snake River Canyon or into Twin Falls County. Access to Twin Falls is afforded by an intersection with US 93 at Exit 173; US 93 southbound crosses the Snake River via the Perrine Bridge. After Twin Falls, I-84 continues through Burley and Heyburn. Approximately east of Declo in rural Cassia County, I-84 meets the western terminus of the western section of I-86. While I-86, along with US 30 heads east, then northeast to

American Falls The American Falls is the second largest of the three waterfalls that together are known as Niagara Falls on the Niagara River along the Canada–United States border. Unlike the much larger Horseshoe Falls, of which approximately 90% is in On ...

and Pocatello (following the

), I-84 heads southeast to the border with

Utah Utah is a landlocked state in the Mountain states, Mountain West subregion of the Western United States. It is one of the Four Corners states, sharing a border with Arizona, Colorado, and New Mexico. It also borders Wyoming to the northea ...

. In 2014, the speed limit on rural sections of I-84 in Idaho was raised to .

Utah

From Idaho, I-84 enters Utah at a point approximately 7 miles (11.3 km) from Snowville in Box Elder County. It proceeds southeast through Rattle Snake Pass towards Brigham City where I-84 joins I-15 (just west of Tremonton) for its next . I-84atEcho

Just north of Brigham City, at

Corinne, Utah } Corinne ( ) is a city in Box Elder County, Utah, United States. The population was 809 at the 2020 census, up from the 2010 figure of 685. History For almost ten years from its founding on 25 March 1869, the town of Corinne prospered as th ...

, I-84 joins the route of the

First transcontinental railroad America's first transcontinental railroad (known originally as the "Pacific Railroad" and later as the "Overland Route (Union Pacific Railroad), Overland Route") was a continuous railroad line built between 1863 and 1869 that connected the exis ...

which the highway follows to its terminus. I-15/I-84 heads south to the cities of the Wasatch Front (Or the Ogden-Clearfield Utah Metropolitan part) passing through several smaller communities and then the west side of Ogden before I-84 separates towards Cheyenne, Wyoming, while I-15 heads to Salt Lake City, I-84 follows the

Weber River The Weber River ( ) (Shoshone: Ho-o-pah) is a long river of northern Utah, United States. It begins in the northwest of the Uinta Mountains and empties into the Great Salt Lake. The Weber River was named for American fur trapper John Henr ...

east. As the freeway gradually ascends through Weber Canyon it also passes through several small farming communities, including Morgan, where the

Browning Arms Company Browning Arms Company (originally John Moses and Matthew Sandefur Browning Company) is an American marketer of firearms and fishing gear. The company was founded in Ogden, Utah, in 1878 by brothers John Moses Browning (1855–1926) and M ...

headquarters can be seen from the freeway. Also visible in the canyon is Devil's Slide, an unusual rock formation just off the freeway. Farther up the canyon is the Thousand Mile Tree, planted by

Union Pacific Railroad The Union Pacific Railroad is a Railroad classes, Class I freight-hauling railroad that operates 8,300 locomotives over routes in 23 U.S. states west of Chicago and New Orleans. Union Pacific is the second largest railroad in the United Stat ...

workers to mark from the railroad's origin in

Omaha, Nebraska Omaha ( ) is the List of cities in Nebraska, most populous city in the U.S. state of Nebraska. It is located in the Midwestern United States along the Missouri River, about north of the mouth of the Platte River. The nation's List of United S ...

. The freeway ends at

Echo In audio signal processing and acoustics, an echo is a reflection of sound that arrives at the listener with a delay after the direct sound. The delay is directly proportional to the distance of the reflecting surface from the source and the lis ...

, a near ghost town that before served as a stopover for the railroad, at a junction with

Interstate 80 Interstate 80 (I-80) is an east–west transcontinental freeway that crosses the United States from San Francisco, California, to Teaneck, New Jersey, in the New York metropolitan area. The highway was designated in 1956 as one of the ori ...

, to Cheyenne, Wyoming, and US 189, to Jackson, Wyoming. Also near the junction are Echo Reservoir and Echo Dam. The Utah sections of I-84 that are not concurrent with

Interstate 15 Interstate 15 (I-15) is a major Interstate Highway in the Western United States, running through Southern California and the Intermountain West. I-15 begins near the Mexican border in San Diego County and stretches north to Alberta, Ca ...

are defined at Utah Code Annotated § 72-4-114(4).

History

The Portland to Utah corridor was proposed as one of the national "toll superhighways" in a 1939 report by the

Bureau of Public Roads The Federal Highway Administration (FHWA) is a division of the United States Department of Transportation that specializes in highway transportation. The agency's major activities are grouped into two programs, the Federal-aid Highway Program a ...

. It was formally included in the

Interstate Highway System The Dwight D. Eisenhower National System of Interstate and Defense Highways, commonly known as the Interstate Highway System, or the Eisenhower Interstate System, is a network of controlled-access highways that forms part of the National Hi ...

, created in 1956, and was originally proposed to be numbered as Interstate 82; however, it was never signed with this designation, and the Interstate 82 designation was later assigned to a different road that connects

Ellensburg, Washington Ellensburg is a city in and the county seat of Kittitas County, Washington, United States. It is located just east of the Cascade Range near the junction of Interstate 90 in Washington, Interstate 90 and Interstate 82. The population was 18,666 ...

, to

Yakima, Washington Yakima ( or ) is a city in and the county seat of Yakima County, Washington, United States, and the state's 11th most populous city. As of the 2020 census, the city had a total population of 96,968 and a metropolitan population of 256,728. The ...

, the Tri-Cities region, and Hermiston, Oregon. The freeway was assigned the designation of I-80N in the 1958 plan, in part to correspond with US 30. The Portland segment of then-I-80N was proposed to run on the Mount Hood Freeway and a section of I-205. Plans for this were officially dropped in 1974 after a successful freeway revolt. The

American Association of State Highway and Transportation Officials The American Association of State Highway and Transportation Officials (AASHTO) is a standards setting body which publishes specifications, test protocols, and guidelines that are used in highway A highway is any public or private road ...

established guidelines recommending that "suffixed" highways, such as I-80N, be renumbered. In 1977, Idaho officials recommended that I-80N be renumbered to I-84. The motion was seconded by officials in Utah (who initially proposed this as I-82), but opposed by Oregon and Washington. The motion passed on July 7, 1977, and the states were given until July 1, 1980, to implement a coordinated renumbering strategy. After renumbering, I-84 violated the Interstate Highway Numbering Convention by being south of the modern incarnation of I-82.

Major intersections

;Oregon * in Portland * in Portland * near Hermiston ;Idaho * in

* near Declo ;Utah * from Tremonton to Ogden * in

Auxiliary routes

Boise, Idaho Boise ( ) is the List of capitals in the United States, capital and List of cities in Idaho, most populous city of the U.S. state of Idaho. As of the 2020 United States census, 2020 census, there were 235,685 people residing in the city. Loca ...

: I-184

References

External links

* {{DEFAULTSORT:Interstate 84 (Oregon-Utah) Interstate 84 84 west 84 west