Washington (state) Washington (state) Washington (), officially the State of Washington, is a state in the Pacific Northwest region of the United States. Named for George Washington, the first president of the United States, the state was made out of the western part of the Washington Territory, which was ceded by Britain in 1846 in accordance with the Oregon Treaty in the settlement of the Oregon boundary dispute. It was admitted to the Union as the 42nd state in 1889. Olympia is the state capital; the state's largest city is Seattle. Washington is sometimes referred to as Washington State, to distinguish it
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