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 510 also became (I-5) in 1968. SR 510 between I-5 and Pacific Avenue was reconstructed and widened in late 2003, with the addition of a roundabout at the Pacific Avenue intersection. The I-5 interchange will be replaced in 2020 with a diverging diamond interchange that began construction in October 2018. The interchange will be the first diverging diamond constructed in Washington and is estimated to cost $72 million, with funding provided by the state legislature's 2015 Connecting Washington package. State Route 510 Alternate, also known as the Yelm Loop, is a partially completed bypass of Yelm. The first, section opened to