Interstate 90 (I-90) is a transcontinental
Interstate Highway
The Dwight D. Eisenhower National System of Interstate and Defense Highways, commonly known as the Interstate Highway System, is a network of controlled-access highways that forms part of the National Highway System in the United States. Th ...
that runs east–west across the northern United States. Within the state of
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 Wyom ...
, the freeway travels for from the
Washington
Washington commonly refers to:
* Washington (state), United States
* Washington, D.C., the capital of the United States
** A metonym for the federal government of the United States
** Washington metropolitan area, the metropolitan area centered o ...
border near
Spokane
Spokane ( ) is the largest city and county seat of Spokane County, Washington, United States. It is in eastern Washington, along the Spokane River, adjacent to the Selkirk Mountains, and west of the Rocky Mountain foothills, south of the Ca ...
to
Coeur d'Alene and the
panhandle region at the north end of the state. After traveling through the
Silver Valley along the
Coeur d'Alene River
The Coeur d'Alene River flows from the Silver Valley into Lake Coeur d'Alene in the U.S. state of Idaho. The stream continues out of Lake Coeur d'Alene as the Spokane River.
Before the Bunker Hill Smelter in the Kellogg area, which mined lead a ...
in the
Bitterroot Range
The Bitterroot Range is a mountain range and a subrange of the Rocky Mountains that runs along the border of Montana and Idaho in the northwestern United States. The range spans an area of and is named after the bitterroot (''Lewisia rediviva' ...
, I-90 crosses into
Montana
Montana () is a state in the Mountain West division of the Western United States. It is bordered by Idaho to the west, North Dakota and South Dakota to the east, Wyoming to the south, and the Canadian provinces of Alberta, British Columbi ...
at
Lookout Pass
Lookout Pass is a mountain pass in the Rocky Mountains of the northwestern United States. In the Coeur d'Alene Mountains of the Bitterroot Range, the pass is on the border between Idaho and Montana, traversed by Interstate 90 (formerly U.S. Rout ...
.
I-90 was created by the federal government in 1957, following the general route of
U.S. Route 10 (US 10) and the mid-19th century
Mullan Road
Mullan Road was the first wagon road to cross the Rocky Mountains to the Inland of the Pacific Northwest. It was built by U.S. Army troops under the command of Lt. John Mullan, between the spring of 1859 and summer 1860. It led from Fort Benton, ...
constructed by the U.S. Army. The freeway was constructed in stages between 1960 and 1992.
Route description
Interstate 90 enters Idaho at a crossing of the
Spokane River
The Spokane River is a tributary of the Columbia River, approximately long, in northern Idaho and eastern Washington in the United States. It drains a low mountainous area east of the Columbia, passing through the Spokane Valley and the city of ...
in the community of
State Line in
Kootenai County
Kootenai County ( ) is located in the U.S. state of Idaho. In 2020, the United States Census Bureau estimated the county's population at 171,362, making it the third-most populous county in Idaho and by far the largest in North Idaho, the count ...
, approximately east of
Spokane, Washington
Spokane ( ) is the largest city and county seat of Spokane County, Washington, United States. It is in eastern Washington, along the Spokane River, adjacent to the Selkirk Mountains, and west of the Rocky Mountain foothills, south of the Canada ...
. The freeway travels northeast through the
Rathdrum Prairie
The Rathdrum Prairie is a flat in the U.S. state of Idaho. The prairie contains the cities of Coeur d'Alene, Post Falls, Hayden, Rathdrum, State Line, and Huetter. The prairie also contains part of the Spokane Valley–Rathdrum Prairie Aquife ...
and into the outskirts of
Post Falls
Post Falls is a city in Kootenai County, Idaho, between Coeur d'Alene and Spokane, Washington. It is a suburb of Coeur d'Alene, to the east, and a bedroom community to Spokane, to the west. The population was 38,485 at the time of the 2020 cens ...
, passing several retailers and a
business park
A business park or office park is a designated area of land in which many office buildings are grouped together. These types of developments are often located in suburban areas where land and building costs are more affordable, and are typically ...
along the Spokane River. I-90 continues east along the river, paralleled to the south by the
North Idaho Centennial Trail
The North Idaho Centennial Trail is a paved trail in Idaho used for transportation and recreational activities. Extending from Higgens Point on the northeast side of Lake Coeur d'Alene, a popular place for bald eagle watchers in early winter, the ...
and a section of the
BNSF Railway
BNSF Railway is one of the largest freight railroads in North America. One of seven North American Class I railroads, BNSF has 35,000 employees, of track in 28 states, and nearly 8,000 locomotives. It has three transcontinental routes that ...
, and passes near the eponymous
Post Falls
Post Falls is a city in Kootenai County, Idaho, between Coeur d'Alene and Spokane, Washington. It is a suburb of Coeur d'Alene, to the east, and a bedroom community to Spokane, to the west. The population was 38,485 at the time of the 2020 cens ...
and the city's downtown, served by a signed
business route
A business route (or business loop, business spur, or city route) in the United States is a short special route connected to a ''parent'' numbered highway at its beginning, then routed through the central business district of a nearby city or ...
. The freeway intersects
State Highway 41 (SH-41) and continues through the city's eastern residential neighborhoods and passes the nearby town of
Huetter
Huetter is a city in Kootenai County, Idaho, United States. The population was 100 at the 2010 census.
Geography
Huetter is located at (47.703759, -116.848870).
According to the United States Census Bureau, the city has a total area of , all ...
. I-90 then reaches
Coeur d'Alene, the largest city in northern Idaho, and intersects a business route and
US-95, the state's main north–south highway, near the
Kootenai Medical Center
The Kutenai ( ), also known as the Ktunaxa ( ; ), Ksanka ( ), Kootenay (in Canada) and Kootenai (in the United States), are an indigenous people of Canada and the United States. Kutenai bands live in southeastern British Columbia, northern ...
.
The freeway travels around the north and east sides of central Coeur d'Alene, intersecting several local streets in the process, and turns southeast towards
Fernan Lake Fernan or Fernán is both a given name and a surname. Notable people with the name include:
* Fernán Blázquez de Cáceres, Spanish nobleman
* Fernán Caballero (1796–1877), Spanish novelist
* Fernando Fernán Gómez (1921–2007), Spanish acto ...
and
Lake Coeur d'Alene
Lake Coeur d'Alene, officially Coeur d'Alene Lake ( ), is a natural dam-controlled lake in North Idaho, located in the Pacific Northwest region of the United States. At its northern end is the city of Coeur d'Alene. It spans in length and range ...
on the Spokane River. I-90 ascends Potlatch Hill and makes several stair-step turns to follow the northern shore of Lake Coeur d'Alene while traversing several forested hills. It passes over a valley overlooking Bennett Bay on the
Veterans Memorial Centennial Bridge
The Veterans Memorial Centennial Bridge (formerly known as the Bennett Bay Centennial Bridge) is a freeway bridge in Idaho. The bridge carries Interstate 90 over a valley above Bennett Bay, an arm of Lake Coeur d'Alene.
Construction of the bridge ...
, a high concrete bridge that was completed in 1987. The freeway descends from the hills and travels southeasterly along Wolf Lodge Bay, passing
Coeur d'Alene Parkway State Park
Coeur d'Alene Parkway State Park is a paved trail in Kootenai County, Idaho, United States. The parkway is located south of Coeur d'Alene along the north shore of Lake Coeur d'Alene. It is a portion of the North Idaho Centennial Trail. Park ...
and intersecting the northern terminus of the
Lake Coeur d'Alene Scenic Byway (
SH-97) at the east end of the lake. I-90 continues east along Cedar Creek into the
Coeur d'Alene Mountains
The Coeur d'Alene Mountains are the northwesternmost portion of the Bitterroot Range, part of the Rocky Mountains, located in northern Idaho and westernmost Montana in the Western United States.
The mountain range spans an area of and its two ...
, part of a
national forest,
and reaches
Fourth of July Summit
Fourth of July Summit is a mountain pass in the Rocky Mountains of the northwestern United States, located in northern Idaho. Its elevation is above sea level on Interstate 90 in central Kootenai County, east of the city of Coeur d'Alene.
Th ...
at an elevation of .
![I-90IDWallace](https://upload.wikimedia.org/wikipedia/commons/0/0e/I-90IDWallace.jpg)
From the summit, I-90 continues southeast along Fourth of July Canyon towards the
Coeur d'Alene River
The Coeur d'Alene River flows from the Silver Valley into Lake Coeur d'Alene in the U.S. state of Idaho. The stream continues out of Lake Coeur d'Alene as the Spokane River.
Before the Bunker Hill Smelter in the Kellogg area, which mined lead a ...
valley and intersects
SH-3
The Sikorsky SH-3 Sea King (company designation S-61) is an American twin-engined anti-submarine warfare (ASW) helicopter designed and built by Sikorsky Aircraft. A landmark design, it was one of the first ASW rotorcraft to use turboshaft engi ...
near
Rose Lake. The freeway bends northward around a hill and travels east into the river valley, passing
Cataldo and the
Old Mission State Park
Coeur d'Alene's Old Mission State Park is heritage-oriented in the western United States in northern Idaho, preserving the Mission of the Sacred Heart, or Cataldo Mission, a national historic landmark. The park contains the church itself, the ...
, home to the state's oldest standing building. In Cataldo, it also crosses the river and the
Trail of the Coeur d'Alenes
The Trail of the Coeur d'Alenes is a rail trail in the northwest United States, in northern Idaho. It follows the former Union Pacific Railroad right-of-way from Mullan, a mountain mining town near the Montana border, westward to Plummer, a to ...
, a major rail trail that follows the highway into the
Bitterroot Range
The Bitterroot Range is a mountain range and a subrange of the Rocky Mountains that runs along the border of Montana and Idaho in the northwestern United States. The range spans an area of and is named after the bitterroot (''Lewisia rediviva' ...
.
I-90 crosses into
Shoshone County, one of only two counties along the highway within Idaho, and continues along the north sides of
Pinehurst and
Smelterville, passing the
Shoshone County Airport at the latter. The freeway travels southeasterly through
Kellogg, passing the
Silver Mountain Resort and its
ski gondola, and continues around the towns of
Osburn and
Silverton along the north bank of the
South Fork Coeur d'Alene River
The Coeur d'Alene River flows from the Silver Valley into Lake Coeur d'Alene in the U.S. state of Idaho. The stream continues out of Lake Coeur d'Alene as the Spokane River.
Before the Bunker Hill Smelter in the Kellogg area, which mined lead a ...
at the bottom of the narrow
Silver Valley.
I-90 also intersects a set of business routes in Osburn and Silverton that loop back to the freeway.
The freeway turns east in the town of
Wallace
Wallace may refer to:
People
* Clan Wallace in Scotland
* Wallace (given name)
* Wallace (surname)
* Wallace (footballer, born 1986), full name Wallace Fernando Pereira, Brazilian football left-back
* Wallace (footballer, born 1987), full name ...
, also served by its own business route, and travels to the north of downtown on an elevated viaduct cut into a nearby hill. At the east end of Wallace, I-90 intersects
SH-4, which connects to the
ghost town
Ghost Town(s) or Ghosttown may refer to:
* Ghost town, a town that has been abandoned
Film and television
* Ghost Town (1936 film), ''Ghost Town'' (1936 film), an American Western film by Harry L. Fraser
* Ghost Town (1956 film), ''Ghost Town'' ...
of
Burke
Burke is an Anglo-Norman Irish surname, deriving from the ancient Anglo-Norman and Hiberno-Norman noble dynasty, the House of Burgh. In Ireland, the descendants of William de Burgh (–1206) had the surname ''de Burgh'' which was gaelicised ...
. The highway continues along the south side of the river and Trail of the Coeur d'Alenes as it ascends further into the mountains and meanders around hills and gulches. The trail ends at the town of
Mullan,
named for road-building U.S. Army captain
John Mullan and home to a business route,
and I-90 continues east along the
Northern Pacific Trail. The freeway travels uphill from the river along a southern ridge and passes a
scenic viewpoint
A scenic viewpoint – also called an observation point, viewpoint, viewing point, vista point, lookout, scenic overlook,These terms are more commonly used in North America. etc. – is an elevated location where people can view scenery (often w ...
commemorating the 1903
Willow Creek avalanche
Willows, also called sallows and osiers, from the genus ''Salix'', comprise around 400 speciesMabberley, D.J. 1997. The Plant Book, Cambridge University Press #2: Cambridge. of typically deciduous trees and shrubs, found primarily on moist s ...
. I-90 then turns south and leaves Idaho at
Lookout Pass
Lookout Pass is a mountain pass in the Rocky Mountains of the northwestern United States. In the Coeur d'Alene Mountains of the Bitterroot Range, the pass is on the border between Idaho and Montana, traversed by Interstate 90 (formerly U.S. Rout ...
, elevated above sea level and located adjacent to the
Lookout Pass Ski and Recreation Area
Lookout Pass Ski and Recreation Area is a ski area in the western United States. It is at Lookout Pass on Interstate 90, on the border of Idaho and Montana, east of Mullan, Idaho. It has a summit elevation of on Eagle Peak and on Runt Mountain ...
.
The freeway
continues into
Montana
Montana () is a state in the Mountain West division of the Western United States. It is bordered by Idaho to the west, North Dakota and South Dakota to the east, Wyoming to the south, and the Canadian provinces of Alberta, British Columbi ...
and travels through the cities of
Missoula
Missoula ( ; fla, label=Salish language, Séliš, Nłʔay, lit=Place of the Small Bull Trout, script=Latn; kut, Tuhuⱡnana, script=Latn) is a city in the U.S. state of Montana; it is the county seat of Missoula County, Montana, Missoula Cou ...
,
Butte
__NOTOC__
In geomorphology, a butte () is an isolated hill with steep, often vertical sides and a small, relatively flat top; buttes are smaller landforms than mesas, plateaus, and tablelands. The word ''butte'' comes from a French word mea ...
,
Bozeman
Bozeman is a city and the county seat of Gallatin County, Montana, United States. Located in southwest Montana, the 2020 census put Bozeman's population at 53,293, making it the fourth-largest city in Montana. It is the principal city of th ...
, and
Billings
Billings is the largest city in the U.S. state of Montana, with a population of 117,116 as of the 2020 census. Located in the south-central portion of the state, it is the seat of Yellowstone County and the principal city of the Billings Metrop ...
.
I-90 is the only Interstate in
northern Idaho
The Idaho Panhandle—locally known as North Idaho—is a salient region of the U.S. state of Idaho encompassing the state's 10 northernmost counties: Benewah, Bonner, Boundary, Clearwater, Idaho, Kootenai, Latah, Lewis, Nez Perce, and Shosho ...
and a major east–west route, forming part of a transcontinental highway.
At , it is the second-shortest mainline Interstate in the state, after
Interstate 86, and the third-longest. The entire highway was designated as the
Purple Heart
The Purple Heart (PH) is a United States military decoration awarded in the name of the President to those wounded or killed while serving, on or after 5 April 1917, with the U.S. military. With its forerunner, the Badge of Military Merit, w ...
Trail by the state legislature in 2008. The Idaho section of I-90 is maintained by the
Idaho Transportation Department
The Idaho Transportation Department (ITD) is the state of Idaho governmental organization responsible for state transportation infrastructure. This includes ongoing operations and maintenance as well as planning for future needs of the state and it ...
(ITD), which conducts an annual survey of traffic on certain highway segments that is expressed in terms of
average annual daily traffic
Annual average daily traffic, abbreviated AADT, is a measure used primarily in transportation planning, transportation engineering and retail location selection. Traditionally, it is the total volume of vehicle traffic of a highway or road for a y ...
(AADT), a measure of traffic volume for any average day of the year. Traffic volumes on I-90 ranged from a minimum of 7,861 near Mullan and 60,729 in Huetter on an average day in 2017.
History
Interstate 90 from Coeur d'Alene to Lookout Pass roughly follows the route of the
Mullan Road
Mullan Road was the first wagon road to cross the Rocky Mountains to the Inland of the Pacific Northwest. It was built by U.S. Army troops under the command of Lt. John Mullan, between the spring of 1859 and summer 1860. It led from Fort Benton, ...
, constructed in 1859–60 by the U.S. Army and civilian volunteers led by captain
John Mullan. Mullan received a series of appropriations from U.S. Congress from 1855 to 1860, totaling $230,000, to build the first engineered road west of the
Mississippi River
The Mississippi River is the second-longest river and chief river of the second-largest drainage system in North America, second only to the Hudson Bay drainage system. From its traditional source of Lake Itasca in northern Minnesota, it f ...
and connect
Fort Walla Walla
Fort Walla Walla is a United States Army fort located in Walla Walla, Washington. The first Fort Walla Walla was established July 1856, by Lieutenant Colonel Edward Steptoe, 9th Infantry Regiment. A second Fort Walla Walla was occupied Septemb ...
to
Fort Benton.
The road also followed the
Coeur d'Alene River
The Coeur d'Alene River flows from the Silver Valley into Lake Coeur d'Alene in the U.S. state of Idaho. The stream continues out of Lake Coeur d'Alene as the Spokane River.
Before the Bunker Hill Smelter in the Kellogg area, which mined lead a ...
and its south fork, which was long used by the
Coeur d'Alene people
The Coeur d'Alene (also ''Skitswish''; natively ''Schi̲tsu'umsh'') are a Native American nation and one of five federally recognized tribes in the state of Idaho.
The Coeur d'Alene have sovereign control of their Coeur d'Alene Reservation, w ...
to visit hunting grounds in modern-day
Montana
Montana () is a state in the Mountain West division of the Western United States. It is bordered by Idaho to the west, North Dakota and South Dakota to the east, Wyoming to the south, and the Canadian provinces of Alberta, British Columbi ...
.
Other sections of I-90 were built over the
Yellowstone Trail
The Yellowstone Trail was the first transcontinental automobile highway through the upper tier of states in the United States, established on May 23, 1912. It was an Auto Trail that ran from the Atlantic Ocean in Plymouth, Massachusetts, throug ...
and
U.S. Route 10,
though some parts of I-90 were cut as new roadway.
The link from Post Falls to the Washington state border was completed in 1972 at a cost of $1.1 million to upgrade the existing road and build a new bridge over the Spokane River.
The small town of
Wallace
Wallace may refer to:
People
* Clan Wallace in Scotland
* Wallace (given name)
* Wallace (surname)
* Wallace (footballer, born 1986), full name Wallace Fernando Pereira, Brazilian football left-back
* Wallace (footballer, born 1987), full name ...
in the Silver Valley still prides itself on having what was the last stoplight on I-90. Its downtown has many historical buildings, which would have been wiped out by the original planned route of the freeway,
so in 1976, city leaders had the downtown placed on the
National Register of Historic Places
The National Register of Historic Places (NRHP) is the United States federal government's official list of districts, sites, buildings, structures and objects deemed worthy of preservation for their historical significance or "great artistic v ...
.
Alternatives discussed in 1963 included tunnels and twin levels.
As a result, the federal government was forced at great expense to reroute the freeway to the northern edge of downtown and elevate it. Work on that section was resumed in 1984, and it opened in September 1991.[Idaho Transportation Department](_blank)
A bicycle path is routed beneath part of that segment. Before the move to the viaduct, I-90 went from a freeway at the western edge of Wallace, then turned to surface streets and followed the main arterial as U.S. Route 10 through town, which included the last stoplight on I-90 between Seattle and Boston. Upon reaching the eastern edge of the town it became a limited access divided highway once again.
The interstate also was routed along Lake Coeur d'Alene
Lake Coeur d'Alene, officially Coeur d'Alene Lake ( ), is a natural dam-controlled lake in North Idaho, located in the Pacific Northwest region of the United States. At its northern end is the city of Coeur d'Alene. It spans in length and range ...
as a surface street before the Veterans Memorial Centennial Bridge
The Veterans Memorial Centennial Bridge (formerly known as the Bennett Bay Centennial Bridge) is a freeway bridge in Idaho. The bridge carries Interstate 90 over a valley above Bennett Bay, an arm of Lake Coeur d'Alene.
Construction of the bridge ...
was completed in 1992, traveling further above the lake.
Exit list
Related routes
*
* '' U.S. Route 10''
References
{{DEFAULTSORT:Interstate 90 In Idaho
Idaho
90
Transportation in Kootenai County, Idaho
Transportation in Shoshone County, Idaho