Interstate 90 in Idaho
|Maintained by ITD|
|Length:||73.888 mi (118.911 km)|
|West end:||I‑90 at the Washington state line|
|East end:||I‑90 at the Montana state line|
In the U.S. state of Idaho, Interstate 90 has a 74-mile-long (119 km) routing in the panhandle. Traveling east from Spokane, Washington, I-90 passes through Post Falls and Coeur d'Alene, over Fourth of July Summit, and through the Silver Valley before entering Montana at Lookout Pass.
I-90 is a major east-west route and the only freeway in northern Idaho. I-90 is the third longest stretch of Interstate highway in Idaho. Interstate 84 and Interstate 15 are longer. Interstate 86 and Interstate 184 are shorter. I-90 is the only coast-to-coast Interstate in Idaho.
Interstate 90 enters Idaho and Kootenai County just east of the Spokane River bridge near the community of State Line, the smallest city in Idaho. It proceeds east through Post Falls to Coeur d'Alene, the county seat, and meets U.S. Route 95. I-90 turns southeast and passes north of downtown, which is accessible via an Interstate Business Loop, and Lake Coeur d'Alene. It continues east-southeast to Fourth of July Summit at an elevation of 3,081 feet (939 m) and down to Cataldo, home to the Old Cataldo Mission built 163 years ago in 1853.
Shortly after leaving Cataldo, I-90 enters Shoshone County and passes through or near the communities of Pinehurst, Kellogg, Osburn, Wallace, and Mullan. I-90 leaves the county and state at Lookout Pass at 4,725 feet (1,440 m)) and enters Montana.
Interstate 90 through Idaho was formerly U.S. Route 10, though some parts of I-90 were cut as new roadway. The small town of Wallace 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. 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. 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.
|Kootenai||||0.000||0.000||I‑90 west||Continuation into Washington|
|Post Falls||1.160||1.867||1||Beck Road|
|2.080||3.347||2||Pleasant View Road|
|4.632||7.454||5||I-90 Business Loop east (Spokane Street) – City Center||Exit is just east of northernmost point on I-90|
|5.450||8.771||6||I-90 Business Loop west (Seltice Way) – City Center||Westbound exit and eastbound entrance|
|7.128||11.471||7||SH-41 north – Rathdrum, Spirit Lake|
|Coeur d'Alene||11.290||18.169||11||I-90 Business Loop east (Northwest Boulevard) – City Center|
|12.040||19.377||12||US-95 – Sandpoint, Moscow|
|14.780||23.786||15||I-90 Business Loop west (Sherman Avenue) – City Center|
|||16.882||27.169||17||Mullan Trail Road|
|||22.063||35.507||22||SH-97 south – Harrison, St. Maries|
|||28.380||45.673||28||Fourth of July Pass Recreation Area|
|||34.028||54.763||34||SH-3 south – Rose Lake, St. Maries, Harrison|
|||39.024||62.803||39||Old Mission State Park|
|||47.687||76.745||48||Smelterville, Shoshone County Airport|
|Kellogg||49.715||80.009||49||Bunker Avenue – Silver Mountain|
|50.321||80.984||50||Hill Street||Eastbound exit and westbound entrance|
|50.551||81.354||51||Division Street – Wardner||No westbound entrance|
|Osburn||57.036||91.791||57||I-90 Business Loop east – Osburn|
|||59.553||95.841||60||I-90 Business Loop west – Silverton, Osburn|
|Wallace||60.990||98.154||61||I-90 Business Loop east – Wallace|
|61.948||99.696||62||I-90 Business Loop west / SH-4 east – Wallace, Burke|
|||66.500||107.021||66||Gold Creek||Eastbound exit and entrance|
|||67.353||108.394||67||Morning District, West Mullan|
|Mullan||68.100||109.596||68||I-90 Business Loop east – Mullan||Eastbound exit and westbound entrance|
|||68.908||110.897||69||I-90 Business Loop west – Mullan, East Mullan|
|||73.888||118.911||I‑90 east (Lookout Pass)||Continuation into Montana|
|1.000 mi = 1.609 km; 1.000 km = 0.621 mi
- Interstate 90 Business (Coeur d'Alene, Idaho)
- Interstate 90 Business (Mullan, Idaho)
- Interstate 90 Business (Osburn, Idaho)
- Interstate 90 Business (Post Falls, Idaho)
- Interstate 90 Business (Wallace, Idaho)
- U.S. Route 10
- "Milepoint Log Report" (PDF). Idaho Transportation Department. Retrieved July 11, 2015.
- Idaho Official Highway Map (2007 ed.), Boise, Idaho: Idaho Department of Transportation, 2007
- "Idaho eyes twin-level freeway". Spokane Daily Chronicle (Washington). Associated Press. December 18, 1963. p. 6.
- "Idaho seeking funds to buy right of way for freeway route". Spokane Daily Chronicle (Washington). February 1, 1957. p. a3.
- Leeright, Bob (July 31, 1971). "Displaced residents add to cost of highways". Spokane Daily Chronicle (Washington). Associated Press. p. 5.
- "Plans for Interstate 90 explained to Wallace CC". Spokane Daily Chronicle (Washington). January 23, 1970. p. 3.
- "Wallace Chamber seeks I-90 shift". Spokane Daily Chronicle (Washington). January 18, 1973. p. b3.
- "Wallace freeway hearing ordered by federal judge". Spokesman-Review (Spokane, Washington). Associated Press. July 23, 1976. p. 13.
- "I-90 study includes historic site survey". Spokane Daily Chronicle (Washington). January 10, 1980. p. 10.
- Collin, Matthew (January 26, 1981). "Wallace freeway 12 years overdue". Spokesman-Review (Spokane, Washington). p. 6.
- "Freeway alternatives reviewed for Wallace". Spokane Daily Chronicle (Washington). Associated Press. October 25, 1978. p. 5.
- Bond, Dave (July 18, 1984). "Wallace bypass work to start". Spokesman-Review (Spokane, Washington). p. 1.
- Idaho Transportation Department Archived September 26, 2006, at the Wayback Machine.
- "He stalled Interstate 90 right in the middle of town". Eugene Register-Guard (Oregon). Associated Press. February 13, 1981. p. 15F.
- "Lone stoplight on Interstate 90 to pass by after new bypass". The Bulletin (Bend, Oregon). Associated Press. September 8, 1991. p. A9.