Interstate 90 in Idaho

Interstate 90 (I-90) is a transcontinental Interstate Highway that runs east–west across the northern United States. Within the state of Idaho, the freeway travels for 74 miles (119 km) from the Washington border near Spokane 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 in the Bitterroot Range, I-90 crosses into Montana at Lookout Pass.

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 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 in the community of State Line in Kootenai County, approximately 20 miles (32 km) east of Spokane, Washington. The freeway travels northeast through the Rathdrum Prairie and into the outskirts of Post Falls, passing several retailers and a business park along the Spokane River. I-90 continues east along the river, paralleled to the south by the North Idaho Centennial Trail and a section of the BNSF Railway, and passes near the eponymous Post Falls and the city's downtown, served by a signed business route. The freeway intersects State Highway 41 (SH-41) and continues through the city's eastern residential neighborhoods and passes the nearby town of Huetter. 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.