state route mile long state highway washington highway began continued northeast parallel boundary unincorporated community crossed canada united_states border british_columbia originally county road added state highway system later removed roadway added extension existing state highway reclassified secondary highway named control road relinquished state renamed route description state route known boundary road boundary highway began grade intersection center street known highway turned north followed upstream railroad owned highway traveled northeast east series turns turning north boundary unincorporated community entered canadian customs continued british_columbia history county road connecting british_columbia existed removed road transferred county maintenance removal state highway system officially added state highway system extension state road british_columbia branch washington renumbered highways switched new system removed state highway system control relinquished turned continues maintain roadway significant events occurred major intersections entire highway
Washington State Route 251