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 10 PSH 3 as I-90 was being planned along its route. I-90 opened between Vantage and Snoqualmie Pass in November 1968 and SR 10 replaced US 10 when the state highways were codified in 1970. US 97 was moved onto former SR 131 between Thorp and Virden in 1975, leaving SR 10 without a concurrency and creating SR 970. Washington State Route 10 State Route 10 (SR 10) is a state highway in the U.S. state of Washington. The highway is a remnant of U.S. Route 10 (US 10) in Kittitas County, traveling southeast along the Yakima River from SR 970