U.S. Route 10 Alternate (US 10A) was an alternate route of US 10 that existed between 1941 and 1967. From 1941 to 1947, it ran between Seattle, Washington, and Missoula, Montana. Since its decommissioning, it has been replaced by Idaho State Highway 200, Montana State Highway 200, and US 2. By 1947, it had been rerouted to run concurrently with US 95, as the majority of its former route had been replaced by the western extension of US 2 from Bonners Ferry to Everett. This change led the highway to begin in Coeur d'Alene, Idaho, rather than in Seattle. It would remain in this configuration until its decommissioning in 1967, as I-90 gradually replaced US 10.