State Route 403 (SR 403, now known as the #Altoona–#PillarRock Road) was a state highway in #WahkiakumCounty, in the U.S. state of #Washington. It extended 10.4 miles (16.7 km) from Pillar Rock northwest to SR 4 in #Rosburg. The route served as a connector to Pillar Rock. The highway was #SecondaryStateHighway12C (SSH 12C) from 1943 until 1964, which ran from Pillar Rock to Rosburg. In 1991, SR 403 was removed from the state highway system.