 U.S. Route 12 begins in Aberdeen on a pair of one @-@ way streets , Heron Street eastbound and Wishkah Street westbound . At its western terminus , US 12 intersects US 101 , which goes west along Heron and Wishkah , and south across Grays Harbor to the south side of Aberdeen . The eastbound and westbound lanes of US 12 merge just east of the Wishkah River , near the Grays Harbor Historic Seaport . US 12 then leaves Aberdeen to the east along the Chehalis River , where it passes through the towns of Central Park and Montesano . Between Aberdeen and Elma , US 12 is four lanes wide . The majority of the highway in Washington , however , is a rural two @-@ lane road . 
