Washington State Route 8 Washington State Route 8 State Route 8 (SR 8) is a state highway in Grays Harbor and Thurston counties, of the U.S. state of Washington. It extends from U.S. Route 12 (US 12) in the city of Elma, east to an interchange with US 101 about northwest of the state capital, Olympia. SR 8 intersects SR 108 west of McCleary. The route connects Elma and Olympia as part of a corridor between Aberdeen and the Puget Sound region. The highway was part of the Elma – Grand Mound branch of Primary State Highway 9 (PSH 9 EG) from 1937 until
Washington State Route 8 Washington State Department of Transportation (WSDOT) replaced the previous system of Primary and Secondary Highways with a new system called State Routes, which is still in use today. Later in 1967, US 12 was extended from Lewiston, Idaho westward to Aberdeen. It was approved on June 20, 1967, and it replaced the route of US 410, therefore making the highway obsolete. Since US 12 used the all-weather White Pass and SR 8 from Elma to Grand Mound, and US 410 used Chinook Pass, which was closed during the winter, US 12 bypassed US 410 and what is now SR 8.