Interstate 82 (I-82) is an Interstate Highway in the Pacific Northwest region of the United States that travels through parts of Washington and Oregon. It runs from its northwestern terminus at I-90 in Ellensburg, Washington, to its southeastern terminus at I-84 in Hermiston, Oregon. The highway passes through Yakima and the Tri-Cities, and is also part of the link between Seattle and Salt Lake City, Utah. I-82 travels concurrently with U.S. Route 97 (US 97) between Ellensburg and Union Gap; US 12 from Yakima to the Tri-Cities; and US 395 from Kennewick to Umatilla, Oregon.
I-82 primarily serves the Yakima Valley agricultural region, following the Yakima and Columbia rivers southeastward to the Tri-Cities. The highway enters the valley from the north by crossing the Manastash Ridge, which separates Yakima from the Kittitas Valley. I-82 bypasses the Tri-Cities by traveling southwest around Richland and Kennewick and then turns south to cross the Columbia River on the Umatilla Bridge. Its only auxiliary route, I-182, connects the highway to Richland and Pasco in the Tri-Cities.
The I-82 corridor was originally used by several state and national highways, including the Inland Empire Highway and US 410, which were built in the early 20th century. The federal government created I-82 in late 1957 to serve military facilities in the region, replacing an earlier designation for what is now I-84. The first section of I-82 to be constructed was the easterly bypass of Yakima, which opened in 1963 and was gradually extended north to Ellensburg by 1971. The Yakima Valley section, connecting Union Gap to Prosser, was constructed between 1977 and 1982.
The routing of the highway between Prosser and I-84 was very controversial among Tri-Cities residents, who lobbied for a longer I-82 alignment to serve them. Oregon legislators and highway officials remained opposed to a routing that bypassed Umatilla, leading to several attempts at finding a compromise along the Wallula Gap or in other areas southeast of the Tri-Cities. In 1973, Oregon and Washington adopted a federal compromise to build I-82 through Umatilla and around the outskirts of the Tri-Cities with a spur route (I-182) to serve the area directly. The Tri-Cities section opened in 1986 while in Oregon, the final section of I-82 was completed in 1988. In the early 2000s, Oregon highway officials examined plans to extend I-82 farther south through eastern Oregon and towards California, but they were not considered for further study.
Route description
I-82 travels through a part of the Inland Northwest in a generally northwest–southeast direction along the Yakima and Columbia rivers.. The four-lane divided highway forms part of the link between Seattle and the inland West, which includes Boise, Idaho and Salt Lake City, Utah. I-82 is a component of the Interstate Highway System and is also designated as an important national highway under the National Highway System. It is also listed as a Highway of Statewide Significance by the Washington state government. I-82 has one auxiliary route, I-182, a spur route that serves the Tri-Cities region. It also has two child state highways in Washington: State Route 821 (SR 821) that runs from Selah to Ellensburg, and SR 823 that runs from Yakima to Selah.
I-82 is maintained by the Washington State Department of Transportation (WSDOT) and the Oregon Department of Transportation (ODOT) within their respective states. Both agencies conduct annual surveys of traffic on segments of the freeway, the results of which are expressed in terms of annual average daily traffic (AADT), a measure of traffic volume for any average day of the year. The most heavily trafficked and the least trafficked sections of I-82 are located in Washington; the busiest section is in downtown Yakima near SR 24, which carried a daily average of 52,000 vehicles in 2016, and the least-trafficked section is the terminus at I-90 near Ellensburg, which carried 9,100 vehicles. In 2016, ODOT's measurements of average daily traffic ranged from a minimum of 13,700 vehicles at Powerline Road near Hermiston to a maximum of 21,700 vehicles at the Umatilla Bridge.
Yakima Valley
I-82 begins southeast of Ellensburg, Washington, at a trumpet interchange with I-90, the state's major east–west freeway. I-82 travels southward in a concurrency with US 97, which continues northwest along I-90 around Ellensburg and intersects with SR 821 at Thrall on the southern edge of the Kittitas Valley. The freeway climbs the Manastash Ridge, traveling southeastward around Yakima River Canyon, where SR 821 runs as a meandering scenic byway. Here, I-82 also forms the western edge of the Yakima Firing Range, a military training and exercise facility that stretches across the plateau to the Columbia River Gorge. The freeway reaches its highest point at Vanderbilt Gap, which is above sea level and only lower than Snoqualmie Pass on I-90. From the gap, the highway crosses into Yakima County and turns southwestward as it begins its descent from the ridge.
Just north of Selah, I-82 crosses the Fred G. Redmon Bridge, a , twinned arch bridge that spans Selah Creek. At the time of its opening in 1971, the Redmon Bridge was the longest concrete-arch bridge in North America at , losing its record in 1993 to new bridges in St. Paul, Minnesota, and Franklin, Tennessee. Southwest of the bridge, the freeway passes several farms and industrial buildings before reaching an interchange with the southern end of SR 821. I-82 continues on the eastern bank of the Yakima River to the east of Selah and intersects SR 823 in Selah Gap, a narrow canyon between two arms of the Yakima Ridge. The freeway, which runs parallel to a section of SR 823 in its median, crosses the Yakima and Naches rivers at their confluence and enters Yakima.
On the southern side of the confluence, I-82 and US 97 intersect US 12, a major cross-state highway that uses White Pass to travel over the Cascade Mountains, and begins a concurrency with it. The three highways travel southward along the Yakima River, veering east of downtown Yakima and its inner neighborhoods. The freeway passes through several urban interchanges, including the western terminus of SR 24 at Nob Hill Boulevard and a hybrid dogbone–partial cloverleaf interchange at the Valley Mall. I-82 continues southward through Union Gap and splits from US 97 at the eponymous canyon, where it crosses the Yakima River with US 12.
I-82 and US 12 travel southeastward in the shadow of the Rattlesnake Hills and along the north side of the Yakima River, opposite from US 97 and the BNSF Railway's Yakima Valley Subdivision on the Yakama Indian Reservation. The freeway follows the Central Washington Railroad and intersects several roads connecting to cities on the southern side of the river, including Wapato and Toppenish, the latter of which is connected via an interchange with SR 22 near Buena. This section of the highway also passes through the Yakima Valley agricultural region, which includes Rattlesnake Hills AVA and Yakima Valley AVA—major areas for wine and hops production, along with other crops. I-82 travels along the southern edge of Zillah and passes the historic Teapot Dome Service Station, a gas station and piece of political and novelty architecture that became a roadside attraction. Past Zillah, the freeway intersects SR 223 in Granger and SR 241 southeast of Sunnyside, bypassing both towns. I-82 continues southeastward through Grandview and toward Prosser at the edge of the Tri-Cities metropolitan area in Benton County.
Tri-Cities and Umatilla
I-82 and US 12 pass several wineries and tasting rooms in northern Prosser before crossing the Yakima River east of the city center. The freeway continues northeastward on the southern side of the Yakima River, running along the bottom of the Horse Heaven Hills. Near Chandler Butte, the highway turns southeastward and intersects SR 224 and SR 225 on the southern side of Benton City. I-82 continues eastward to an interchange with I-182, its sole auxiliary route, at Goose Gap near West Richland; from here, I-182 travels concurrently with US 12 into Richland and Pasco, while I-82 bypasses the Tri-Cities to the southwest, staying south of Badger Mountain. I-82 continues southeastward along the edge of the Horse Heaven Hills to an interchange with US 395 south of Kennewick, where it forms another concurrency. The Kennewick–Plymouth section of the freeway is also signed as part of the Lewis and Clark Trail, a Washington state scenic byway.
I-82 and US 395 travel southward and ascend the Horse Heaven Hills to an intersection with SR 397, a highway that provides an alternate truck route for Kennewick and Finley. The freeway continues southwestward along Bofer and Fourmile canyons, descending from the hills and passing irrigated farmland while approaching the Columbia River. Northeast of Plymouth, it intersects the eastern terminus of SR 14, a cross-state highway that follows the Columbia River westward to Vancouver, and crosses the BNSF Fallbridge Subdivision, which carries Amtrak's Empire Builder passenger trains. I-82 and US 395 cross the Columbia River west of McNary Dam on Umatilla Bridge, which consists of a unique, multiple cantilever, steel truss bridge carrying the eastbound lanes, a newer concrete segmental bridge that carries the westbound lanes, and a multi-use trail for bicyclists and pedestrians.
After crossing into Oregon, the freeway enters Umatilla and intersects US 730, which becomes briefly concurrent with US 395 after it splits from I-82. I-82, designated as the unsigned McNary Highway No. 70 under Oregon's named highway system, continues southwestward across the Umatilla River around central Hermiston. The freeway runs along the edge of the Umatilla Chemical Depot and terminates at an interchange with I-84, which is concurrent with US 30, southwest of Hermiston; I-84 and US 30 continue westward along the Columbia River toward Portland and eastward to Pendleton and Boise, Idaho., with inset maps .
History
Predecessor highways
Several sections of I-82 follow railroads and wagon roads that were built in the late 19th century to connect towns in Washington Territory, generally following early Indian trails. In the 1880s, the Northern Pacific Railway constructed a railroad along the Yakima River between Ellensburg and Pasco as part of its transcontinental route to Tacoma via Stampede Pass. The section through Yakima River Canyon between Ellensburg and North Yakima (now Yakima) bypassed an early toll road constructed by settler Jacob Durr that traveled farther west via Wenas Valley and Shushuskin Canyon.
In 1909, the Washington state government appropriated funds to survey routes through the Yakima Valley as part of a potential extension of the state road system. In 1913, at the suggestion of good roads advocates, the Washington State Legislature established the Inland Empire Highway as one of the trunk routes of its state highway system and appropriated $301,000 (equivalent to $ in dollars) to construct it to modern standards. The highway incorporated several existing and planned county roads from Ellensburg to Pasco; it then continued eastward to Walla Walla and northward to Spokane and the Canadian border near Kettle Falls. The Durr toll road was bypassed by a new highway through the Yakima River Canyon that opened on September 12, 1924, and was fully paved in 1932.