This map shows the section of highway that we close annually. The Ross Dam Trailhead is where we close the North Cascades Highway on the west side. Ross Dam Trailhead is several miles east of the town of Diablo. Silver Star Gate is where we close the highway on the east side.


State Route 20 stretches from Port Townswend on the west, to Newport on the east. The North Cascades Highway starts near Newhalem and runs east over the Cascades towards Twisp.