route washington route major east west highway running washington detroit michigan spans miles state washington numbered highway span entire state west east starting near pacific_ocean crossing idaho state line near crosses cascade range south mount national park portions concurrent interstate interstate majority route parallel interstate highway extended washington portions washington state highway system early highway open white pass added state highway system legislature route approximately miles inception route portion grand mound designated route description begins pair way streets street eastbound street westbound western terminus intersects goes west south harbor south eastbound westbound lanes merge east near harbor historic leaves east passes towns lanes wide majority highway washington rural lane road town exits highway diamond interchange main highway continues east state route heads southeast rochester east runs north continues east town rochester interchanges exit town continues south concurrent exiting exit south highway heads east passes town intersects east runs north town intersects heads north cascade range passing south intersects serves entrance mount national park miles east intersection crosses elevation feet crossing open year round descends mountains intersects west serves pass entrance mount national park east widens lanes approaches city interchange exit runs concurrently bypassing towns paralleling exit near tri cities exit meets western terminus interstate run concurrently east ends intersects heads south town intersecting east north dodge east crossing idaho state line outside consists lane bypass known alignment passes number historical landmarks history created appropriated funds construct maintain highways sparsely settled areas state main highways populated areas continue entirely county control built state aid highways east west crossings including corridor currently served state road climbing east point near amendment renamed state road road moved cascade crossing north defined portion east pass follow point near east mouth replaced state road state road defined cross north pass included law surveyed connected network proposed state roads included westerly extension easterly extension route southeast east surveyed extension state road legislature added routes state highway system formed system primary secondary roads primary roads completely controlled state including maintenance received names secondary roads kept numbers county maintenance replaced state road west extended surveyed replaced state road continued state road majority route added time finally taken secondary state highways route forming continued idaho east original survey curved south state road near oregon state line bypassed designation instead continued directly east unlike earlier state roads primary roads followed existing county roads incomplete roadway remained secondary state road legislature designated surveyed route near north secondary state road restructuring system assigned numbers primary state highways state road primary route greatly expanded taking entire east pacific highway secondary state road realigned starting near heading north instead east alongside old pass west summit new state road named included roads vicinity mount national park road pass built roads connect included numbering designation including state road spur added state road connecting grand mound creating route west added state highway system west east highway system laid finalized late route connected following olympic highway state road concurrent state road state road differed present followed route despite state highway system crossing columbia river gorge opened traffic near east white pass close original plan east half state road added state highway system branch highway roadway pass added state highway system different alignment finally completed dedicated august opening southwest washington highways established ended montana current routing washington followed route extended westward stages extension idaho approved june times early 1960s states idaho washington oregon submitted plans westward extension officials vancouver washington oregon plan submitted highway going far plans rejected washington introduced new system sign route numbers signed present state route grand mound state route extension finally approved june taking routing crossed pass weather white pass replacing signs changed late december bypassed segments new major intersections
U.S. Route 12 in Washington