Getting Oriented
SR-20 leaves I-5 at Burlington and runs east through Sedro-Woolley, Concrete, Marblemount, and Newhalem before climbing into North Cascades National Park. The middle 50 miles cross national park land with no fuel and very limited services. East of the park, the highway drops into the Methow Valley through Mazama, Winthrop, and Twisp. The Mt. Baker Ranger Station in Sedro-Woolley is the western information stop; the Methow Valley Ranger District in Winthrop covers the eastern end.
Trail Overview
One hundred and forty miles of paved highway, point-to-point. The first 25 miles are flat farmland; from Concrete to Marblemount the road follows the Skagit River through forested lowlands. The Skagit Wild and Scenic River system provides bald eagle viewing in winter, with Washington's largest wintering population of eagles concentrated in the gravel bars near Marblemount. Past Newhalem, the road climbs through North Cascades National Park, crosses Rainy Pass and Washington Pass, then drops into the Methow Valley. The two passes are roughly 30 miles apart with a long climb to each. Pull-outs are signed at the Diablo Lake Overlook, Ross Dam, Washington Pass overlook, and several waterfall viewpoints.
Points of Interest
- Skagit River bald eagle viewing. Late November through January between Concrete and Marblemount.
- North Cascades Visitor Center, Newhalem. NPS visitor center on the western approach.
- Diablo Lake Overlook. Famous turquoise reservoir view, mid-highway in North Cascades National Park.
- Ross Lake National Recreation Area. Foot, water, and limited road access.
- Rainy Pass. Pacific Crest Trail crossing at 4,855 feet.
- Washington Pass overlook. Walk-in viewpoint at 5,477 feet, with Liberty Bell Mountain and the Early Winters Spires.
- Methow Valley. Mazama, Winthrop, and Twisp on the eastern end, with full services.
- Hart's Pass spur. Off the Methow Valley near Mazama, the highest maintained road in Washington.
- Pasayten Wilderness. Borders the highway on the north past Mazama.
- Lake Chelan National Recreation Area. Foot and water access via Stehekin from Rainy Pass area.
Where to Camp
Newhalem Creek, Goodell Creek, and Colonial Creek Campgrounds (NPS) sit on the western end inside North Cascades National Park. Klipchuck and Lone Fir Campgrounds (USFS) sit on the eastern descent in Okanogan-Wenatchee National Forest. Dispersed camping is allowed on national forest land off the side roads east of Mazama. Ross Lake's water-access boat-in campsites are reservable through the park. Mazama, Winthrop, and Marblemount have commercial lodging.
Tips for a Safe and Enjoyable Trip
- Check WSDOT's mountain pass page before driving in spring or fall. The full highway closes most years from late November through late April.
- Carry chains in shoulder seasons; spring and fall snow squalls hit the passes without warning.
- No fuel between Marblemount and Mazama, roughly 70 miles. Top off before crossing.
- The highway is two-lane the whole way with limited passing zones. Plan slow Sunday traffic in summer.
- Cell coverage drops out east of Newhalem and stays out until Mazama.
- Bald eagle viewing pull-outs near Marblemount fill quickly on winter mornings; arrive before 10 a.m.
- Wildlife crossings are common; watch for deer at dawn and dusk.
- Wildfire smoke can close the highway in late summer.
