North Cascades Highway (SR-20)
State Route 20
Winthrop, WA
The last road ever built across the North Cascades, climbing past glacier-carved spires and a turquoise lake on its way over the mountains.
The North Cascades Highway is one of the great mountain drives in the country, a ribbon of pavement that climbs over two high passes through some of the most rugged wilderness in the lower forty-eight. Running as State Route 20 across the top of Washington, it links the wet forests of the west side with the dry, sunny Methow Valley and the town of Winthrop in the east, and for the miles in between it belongs entirely to the mountains.
Along its length the road passes glacier-carved granite spires, an unnaturally bright turquoise lake, and trailheads into the heart of North Cascades National Park. There are almost no towns and no services on the high stretch, which is part of what makes it feel less like a highway and more like a passage granted through the range, open only when the mountains allow.
What Guests Love
- The Washington Pass Overlook, a short paved walk to a stunning view of Liberty Bell Mountain and the spires
- The electric turquoise water of Diablo Lake seen from its overlook on the western side
- Trailheads at Rainy Pass and beyond that lead straight into North Cascades high country
- The drama of a road with almost no towns or services, just mountains, for miles
Worth Knowing
- The high section over the passes closes every winter for avalanche danger and reopens in spring, so check the road before you go
- There is no gas or food along the mountain stretch, so fill up in Winthrop or on the west side first
- Weather changes fast at the passes and snow lingers, so carry layers even in summer
- The overlook pullouts fill on clear weekends, so start early for parking and the best light
Details
Winthrop, WA
Learn about North Cascades Highway (SR-20)
The last road across the range
People dreamed of a road across the northern Cascades for nearly eighty years before it happened. Surveyors and boosters pushed the idea from the 1890s onward, but the terrain was so steep, so avalanche-prone, and so remote that the route defeated every attempt for generations. Construction inched forward in fits and starts, and the final section over the passes did not open until September 2, 1972.
That opening made SR-20 the last major highway ever built across the Cascade Range in Washington, and the difficulty of building it is exactly why the drive is so wild. The road had to be threaded through country that resisted roads for a century, so instead of taming the mountains it simply slips among them, which is why a modern paved highway can still feel like a genuine adventure.
Washington Pass and Diablo Lake
The showpiece is Washington Pass, the higher of the two crossings at over five thousand feet. A short, paved, wheelchair-accessible path leads from the parking area to the Washington Pass Overlook, and the view there stops people in their tracks: the sheer granite of Liberty Bell Mountain and the Early Winters Spires rising straight up across the valley, with the highway itself curling far below in a hairpin. It is one of the most photographed viewpoints in the state, and it earns it.
On the western side, the Diablo Lake Overlook looks down on water so vividly turquoise it hardly looks real. The color comes from glacial flour, rock ground to fine powder by the glaciers above and carried into the lake, where it catches and scatters the light. Between these two set pieces the road passes Rainy Pass, waterfalls, and the trailheads that hikers use to disappear into the high country for days.
Driving it, and the seasons that rule it
The mountains decide when you can drive this road. Every year the high section over Rainy and Washington passes closes for winter, sometimes for half the year, because the avalanche danger is simply too great to keep it open and plowed. It reopens in spring after crews clear enormous snow slides, and the reopening date shifts with the weather, so a summer or early-fall trip is the safe bet and a check of the road status is essential before you commit to the crossing.
When it is open, the drive is unforgettable in either direction. From Winthrop, an Old West-themed town in the sunny Methow Valley, you climb from sagebrush and pine up into alpine granite and then down through deep, mossy forest toward Puget Sound, watching the whole climate of the state change through the windshield. Give yourself far more time than the mileage suggests, because you will want to stop at every overlook, and there is no gas or food for the long middle stretch, so start with a full tank.
Closest Boutels
The closest Boutel™ stays, so you can turn this stop into an overnight. Each is an independently owned, editorially selected place to stay.
Things to Do Near Winthrop
Washington Pass Overlook
On the route
The highway's signature stop, a short paved walk to a stunning view of Liberty Bell Mountain and the spires above a hairpin turn.
Diablo Lake Overlook
About 40 miles west of the pass
The classic pullout above the glacier-fed lake, whose turquoise color comes from rock flour carried down by the glaciers.
Winthrop
About 30 miles east
An Old West-themed town in the sunny Methow Valley with boardwalks, shops, and river access, the eastern gateway to the highway.
North Cascades National Park
Along the route
The wilderness the highway passes through, with hundreds of glaciers, backcountry trailheads, and some of the wildest country in the lower forty-eight.