the state highway system was restructured completely, incorporating numbers instead of names. The Olympic Highway became State Road 9, the Pacific Highway became State Road 1, the National Park Highway absorbed the Naches Pass Highway and remained State Road 5, and the Inland Empire Highway became State Road 3, but its branch from Dayton to Clarkston remained a branch of the now non-existent Inland Empire Highway. A system of national highways that improved on the concept of auto trails was formed in late 1925. The final plan for the system—which became the U.S. routes—was approved on November 11, 1926. One of the routes included in the plan was US 410, which extended from US 101 in Aberdeen to US 95 in Lewiston, Idaho. Parts of US 410 were concurrent with other new highways, including US 99 from Olympia to Tacoma and US 97 in Yakima. In 1937, the state highway system changed to a primary and secondary system. US 410 remained the same, but its concurrent state highways had their designations changed by the state. State Road 9 became Primary State Highway 9 (PSH 9), State Road 1 and US 99 became PSH 1, State Road 5 became PSH 5, State Road 3 became PSH 3, and the Inland Empire Highway branch from Dayton to Clarkston became a branch of PSH 3. In 1964, Washington unveiled a new numbering system for highways. Concurrencies with state primary state highways would be repealed in 1970 and US 410 would be a non-concurrent highway. On June 20, 1967, US 12 was extended west from Lewiston, Idaho, over White Pass to Aberdeen, eliminating most of the original route of the highway. The remaining sections were split amongst other routes. The segment from Elma to Olympia became State Route 8 (SR 8). Interstate 5 (I-5) took the Olympia–Tacoma segment, and the Tacoma–Naches segment became SR 410. The last reassurance markers for US 410 were taken down by December 1967. Originally, SR 410 passed through downtown Puyallup and Sumner, following several surface streets (including Main Avenue in Puyallup and Thompson Street, Alder Avenue and Main Street in Sumner) across the two cities. In the late 1960s, construction began on a limited-access bypass of the two city centers. SR 410 was moved onto the new freeway by 1972. In 1973, SR 410 was shortened to its current length after SR 167 was extended to Tacoma. The Mather