In 1987, US 97 was moved across the Columbia River in Chelan County, establishing US 97 Alternate and decommissioning SR 151. US 12 replaced US 410 during its extension west in 1967.

During the 1964 highway renumbering, all four highways were replaced by US 97 and in 1956, the Interstate Highway System was established, including two highways (I-82 and I-90) concurrent with US 97. The Sam Hill Memorial Bridge, originally named the Biggs Rapids Bridge, was first opened on November 1, 1962, but the river has been crossed by a ferry at the same location since the early 1920s.

The state roads became Primary state highways in 1937, keeping their numbers from the previous system and US 10 was moved south in 1940 and its original alignment, including the concurrency, became US 2 in 1946. The United States Numbered Highways were established in 1926 and US 97 was co-signed with all four state roads, including two concurrencies with US 410 and US 10. Since, four early highways formed the modern route of the roadway: State Road 8, State Road 3, State Road 2 and State Road 10, all signed in 1923.

The first segment of what is now US 97 in Washington to be included in the state highway system was a road extending from Wenatchee to Twisp, designated in 1897. An alternate route connects the highway with Chelan. Along the length of the roadway, US 97 is concurrent with State Route 14 (SR 14) in Maryhill, Interstate 82 (I-82) and US 12 between Union Gap and Ellensburg, I-90 briefly in Ellensburg, US 2 between Peshastin and rural Douglas County and SR 20 near Omak. The highway serves major cities such as Goldendale, Yakima, Ellensburg and Wenatchee before continuing towards the Alaska Highway at the Yukon border as British Columbia Highway 97. state of Washington is a 322-mile (518 km) route which traverses from the Oregon state line at the northern end of the Sam Hill Memorial Bridge in Maryhill, north to the Canada–US border in Okanogan County near Oroville. Klickitat, Yakima, Kittitas, Chelan, Douglas, Okanogan Hwy 97 at the Canada–US border near Oroville

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