High Quality Content by WIKIPEDIA articles! State Route 20, also known alternately as the North-Cross Highway, SR 20 or the North Cascades Highway, is a State Highway (Route) in the State of Washington. It travels from an intersection with U.S. Route 101 at Discovery Bay near Port Townsend to Newport at a junction with U.S. Route 2 about 400 feet (122 m) from the Idaho state line. Although U.S. Route 12 has a larger east?west extent, SR 20 is the longest highway in Washington at 436.13 miles (701.88 km), only 5.3 miles (8.6 km) longer than US 12. The highway has been called "The Most Beautiful Mountain Highway in the State of Washington."