Mount St. Helens Worm Flows Backcountry Ski

Mount St. Helens National Volcanic Monument

Southwest Washington/Mount St. Helens, Washington

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Mount St. Helens Worm Flows Backcountry Ski


  • The skin track from the parking lot is part of a network of cross-country ski trails through the sub-alpine forest.- Mount St. Helens Worm Flows Backcountry Ski
  • Many people opt to setup a base camp just below treeline, which lies about 2 miles from the trailhead.- Mount St. Helens Worm Flows Backcountry Ski
  • Just out of the trees, the route switchbacks to gain a small ridge.- Mount St. Helens Worm Flows Backcountry Ski
  • Easy route finding with good visibility.- Mount St. Helens Worm Flows Backcountry Ski
  • - Mount St. Helens Worm Flows Backcountry Ski
  • Looking south to the Oregon Cascades.- Mount St. Helens Worm Flows Backcountry Ski
  • - Mount St. Helens Worm Flows Backcountry Ski
  • Multiple skin tracks lead up the Worm Flows.- Mount St. Helens Worm Flows Backcountry Ski
  • Massive up-draft depositing windblown snow on the south face.- Mount St. Helens Worm Flows Backcountry Ski
  • Great fall line skiing on the Worm Flows route.- Mount St. Helens Worm Flows Backcountry Ski
  • Looking north toward Mount Rainier (14,411').- Mount St. Helens Worm Flows Backcountry Ski
  • Looking west along the crater rim to the true summit.- Mount St. Helens Worm Flows Backcountry Ski
Overview + Weather
Corn skiing. Great views.
Some snowmobile traffic. Weekend crowds.
Southwest Washington/Mount St. Helens, WA
Max slope angle: 
30-45 degrees
Parking Pass: 
Sno-Park Parking Permit (required in OR + WA 11.01 thru 04.30)
Total Distance: 
10.00 mi (16.09 km)
Trailhead Elevation: 
2,700.00 ft (822.96 m)
Vertical descent: 
5,400.00 ft (1,645.92 m)
Current Local Weather:
Adventure Description

Adventure Description


Arguably one of the easiest Cascade volcanoes to climb, Mount St. Helens also provides one of the best ski descents in the Cascade Range. On a warm spring day, the southern exposed Worm Flows route becomes prime-time corn skiing.  The route is best completed with good visibility, as most of the route and the best skiing are well above tree line.

Beginning at the Marble Mountain Sno-Park, Worm Flows is the primary winter route, as the road to the Climbers Bivouac is not plowed during the winter. The sno-park is also a hub for snowmobile traffic in the area, so don't expect peace and quiet if you plan on camping in the lot to get an early start. The route winds through a well-used network of cross-country ski trails before meeting the Worm Flows just above tree line. The Worm Flows get their name from the worm-like features that extend down the southeast flanks of the mountain.

Above the tree line the winter route is yours to choose, and the lava flows create small canyons and ridges that are easy to follow. The ridges are often the best to skin-up, while the small canyons offer protected snow that often makes for better skiing. The route primarily follows the fall line, and it is easy to follow with good-visibility. The last 1,000 feet is a large and gentle bowl that will usually require a switchback or two as the route approaches the summit rim. The true summit sits west of where the Worm Flows route meets the crater rim, but few skiers put in the extra half-mile to reach the true summit.

The ski down offers 4,000 feet of uninterrupted fall line skiing that will quickly make you forget about the ascent. Flowing features and small canyons add some excitement to the relatively straightforward ski. Be aware of wind loaded bowls and terrain traps, as avalanche risks are a main concern during the winter months. Once you reach the tree line, you'll be able to ski your skin track all the way to the car with a few pushes.

Climbing permits are required from November 1 through March 31, but they are free of charge and can be found at the Marble Mountain Sno-Park.

Backcountry Safety

Winter backcountry adventures can be dangerous outdoor activities that pose significant risks as conditions affecting safety (i.e. weather, snowpack stability, avalanche hazard) are constantly changing. Prior to engaging in these activities each individual should get the proper training to make safe decisions and be equipped to use avalanche safety resources and tools. Please visit our Backcountry Skiing and Avalanche Safety post to learn more.

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Nearby Camping + Lodging

(8 within a 30 mile radius)

Nearby Adventures

(51 within a 30 mile radius)

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