This free Washington highway drives you past 300 glaciers and one jaw-dropping national park

It’s free, it’s wild and it’s unforgettable

State Route 20 crosses the North Cascades from the green river valleys to the high desert in about 140 miles, and the whole drive feels like the mountains are testing whether you’re paying attention. Turquoise lakes sit below jagged peaks.

Old-growth cedars line the river. A pass at nearly 5,500 feet drops you into golden larch country before the road unwinds into ranching land on the other side. And the national park you drive straight through?

No entrance fee.

One highway, two completely different worlds

The scenic byway portion of SR 20 runs about 140 miles, from Sedro-Woolley in the wet, green Skagit Valley on the west to Twisp in the sunny, dry Methow Valley on the east.

The highway is part of the Cascade Loop, a longer driving tour through the Washington Cascades. North Cascades National Park sits along the route and draws somewhere between 30,000 and 50,000 visitors a year.

Mount Rainier, about the same distance from Seattle, pulls nearly two million.

Tribes crossed these mountains long before the road did

Long before any road existed here, Native American tribes used this corridor as a trading route between the eastern plateau and the Pacific Coast. That went on for thousands of years.

A wagon road came through in 1896, but fell apart within a decade.

The modern highway didn’t open until 1972, funded in part by the Skagit River Hydroelectric Project. Now it carries a designation as a National Forest Scenic Byway, though the mountains don’t care much what you call it.

Diablo Lake’s color will make you pull over and stare

Diablo Lake runs turquoise, and the reason isn’t algae or a trick of the light. Glaciers grind rock into a fine powder called glacial flour, and streams carry it into the lake.

The particles scatter sunlight, and that’s the color you see. The effect peaks in July, August and September when glacial melt runs hardest.

A pullout called the Diablo Lake Overlook off Highway 20 puts you right above it. The lake sits behind Diablo Dam, completed in 1930 as part of a three-dam system that still powers Seattle.

Ross Lake stretches all the way to Canada

Just past Diablo, Ross Lake comes into view near milepost 134.

It’s the largest of the three reservoirs along the upper Skagit River, and it runs north until it crosses into Canada. Ross Dam, the tallest of the three, went up in stages through the 1940s and 1950s.

The lake draws kayakers, anglers and backpackers who camp at boat-in sites along the shoreline. The surrounding Ross Lake National Recreation Area connects the two separate units of North Cascades National Park.

Washington Pass sits at 5,477 feet with a view worth the climb

Washington Pass is the highest point on the highway at 5,477 feet, and a short paved trail takes you to an overlook above the road. The whole walk takes only a few minutes, and it’s wheelchair accessible.

From the top, Liberty Bell Mountain rises about 2,000 feet directly above the highway. It gets its name from the shape, which resembles the famous bell in Philadelphia.

In the fall, golden larch trees line the ridgeline around it. Photographers come from across the region just for that light.

The easiest hike in the North Cascades ends at a glacial lake

The Rainy Lake Trail runs exactly one mile on a paved path to a lake tucked inside a glacial cirque. Steep cliffs rim the bowl on three sides, and waterfalls drop down the rock faces into the water.

The trail is wheelchair accessible and takes almost no effort, which makes it easy to overlook what you’re actually walking into. The trailhead sits at Rainy Pass, milepost 158 on Highway 20.

You’ll need a Northwest Forest Pass for the parking lot.

Heather-Maple Pass Loop goes where the views open wide

If you want more than a short walk, the Heather-Maple Pass Loop covers 7.2 miles and climbs about 2,000 feet to a ridgeline above the treeline.

The trail moves through wildflower meadows in summer and into larch country in fall, when the whole ridge turns gold. A short side trail branches off to Lake Ann, a glacial cirque lake with a clear view of the peaks.

The trailhead shares the same parking area as the Rainy Lake Trail at Rainy Pass.

Newhalem was built for dam workers and never quite left the past

Newhalem started in 1918 as a company town for Seattle City Light workers building the Skagit dams. At its peak, it housed more than 300 workers and their families.

Today, fewer than 40 people live there, and Seattle City Light still owns the whole town.

Walk the main street and you’ll pass a general store that’s been there since 1922, a vintage Baldwin steam locomotive called Old Number Six that you can climb aboard, and the North Cascades Visitor Center just outside town, run by the National Park Service.

Old-growth cedars and two waterfalls just off the road

Right near Newhalem, the Trail of the Cedars loops three-quarters of a mile through old-growth western red cedar and Douglas fir. A suspension footbridge over the Skagit River connects the trail back to town.

A bridge along Highway 20 gives you a straight-on look at Gorge Creek Falls without leaving your car. Ladder Creek Falls sits a short walk from the Gorge Inn.

None of these stops requires special gear or much time, and they work for anyone in the group regardless of fitness level.

More glaciers here than anywhere else in the Lower 48

North Cascades National Park holds more than 300 glaciers, more than any other park in the contiguous United States. Those glaciers feed the rivers and lakes that put color into everything you’ve been looking at all day.

Several peaks rise above 9,000 feet, with Goode Mountain at the top. Nearly all of the park falls under protection as the Stephen Mather Wilderness.

The park gets a fraction of the visitors that nearby parks see, which means most of the 200-plus miles of trails stay quiet.

Winthrop dressed up as a cowboy town and never changed back

When the North Cascades Highway opened in 1972, the town of Winthrop decided to get ready for the traffic by remaking itself as an Old West destination.

Wooden boardwalks, false-front buildings and hitching posts went up along the main street, and a local ordinance has kept the look in place ever since.

The idea came partly from watching Leavenworth succeed with a Bavarian theme.

In winter, the Methow Valley becomes a different kind of draw, with more than 120 miles of groomed Nordic ski trails, the largest network of its kind in North America.

The road closes every winter and opens when the mountains say so

The highway shuts down at Washington Pass and Rainy Pass every winter because of heavy snow and avalanche danger. The passes can collect up to 15 feet of snow, and avalanches pile more than 20 feet across the road.

On average, crews reopen around April 21 and close again around Nov. 24, but the exact dates shift every year based on conditions. Cell service disappears for long stretches between Marblemount and Mazama.

Check WSDOT’s current road status before you leave, fill the tank in Marblemount heading east or Mazama heading west, and give yourself more time than you think you need.

Visit North Cascades National Park in Washington

North Cascades National Park sits about 100 miles northeast of Seattle and runs along State Route 20. The park has no entrance fee.

The North Cascades Visitor Center in Newhalem and the Wilderness Information Center in Marblemount are the best places to start. Both can help you plan trails, camping and road conditions.

The visitor center in Newhalem is at 502 Newhalem St., Newhalem, WA. Check the official website for current hours, as seasonal schedules vary.

This article was created with AI assistance and human editing.

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