SR 290 begins as a short freeway at a directional T-interchange with east of downtown Spokane. This interchange was originally built for a planned North Spokane Corridor in the 1970s. The freeway continues north to an interchange with 2nd Avenue that only allows eastbound traffic to enter and westbound traffic to exit the freeway. The highway is named Hamilton Street and travels north over Sprague Avenue, BNSF Railway tracks, and the Spokane River before intersecting Trent Avenue, the former route of the roadway prior to 2005. At the intersection, located near Gonzaga University, SR 290 turns east and becomes Trent Avenue before crossing the Spokane River again. Trent Avenue travels northeast through an industrial district, paralleling the Spokane International branch of the Union Pacific Railroad, through Millwood before intersecting, locally named Pines Road. The highway crosses the Spokane River a third time and enters the Trentwood neighborhood of Spokane Valley, where it intersects Sullivan Road by way of a diamond interchange. From Spokane Valley, the roadway travels northeast through farmland to Newman Lake, where it crosses into Idaho and becomes, which continues east to Rathdrum as Trent Road. SR 290 is maintained by the Washington State Department of Transportation, which conducts an annual survey on state highways to measure traffic volume in terms of average annual daily traffic. Average traffic volumes on the highway in 2016 ranged from a minimum of 7,000 vehicles at Havana Street in eastern Spokane to a maximum of 35,000 vehicles at the intersection of Hamilton Street and Trent Avenue. One of the main uses for SR 290 is to connect Interstate 90 to Spokane's University District, which includes the campuses of Gonzaga University, Washington State University, and Eastern Washington University.
History
A road following the Great Northern Railway and Northern Pacific Railway line from Spokane to the Idaho state border at Newman Lake has existed since 1901. In 1937, the road became Secondary State Highway 2H and ran from in Spokane to Wellesley Avenue at the Idaho state border. SSH 2H was scheduled to be designated SR 290 in 1970 after a highway renumbering in 1964. The new designation was made to align with the sign route, now state route, system. In 1967, the eastern terminus of SSH 2H was shifted north to align with . In 1970, the state route system came into effect and SR 290 was established along with a spur route connecting the main highway to . In 2005, the western terminus of SR 290 was moved southeast to an exit with I-90, replacing the spur route. The highway crosses the Spokane River on the East Trent Bridge, which was constructed in 1910 by the Spokane city government. The concrete arch bridge is planned to be closed on June 1, 2020, and will be replaced by a new structure that is set to open in 2023.
Major intersections
Spur route
Washington State Route 290 Spur was a long spur route of SR 290 prior to 2005. The spur route served as a short connector to east of downtown Spokane and ran from SR 290 at the intersection of Trent Avenue and Hamilton Street near Gonzaga University to a directional T-interchange with I-90, via a bridge over the Spokane River. The highway was originally established along with SR 290, which went east from and in downtown Spokane to Idaho. This spur route was proposed to be the southern terminus of the North/South Freeway that would bypass Downtown Spokane and a freeway segment was built, but never finished due to priority going to the Interstate Highways. The western terminus of SR 290 was realigned in 2005, ending at I-90 along the former route of SR 290 Spur. ;Major intersections
