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Mount St. Helens Winter Route: Worm Flows

 4 votes


10.5 Miles 17.0 Kilometers


5,662' 1,726 m


-5,661' -1,726 m



Avg Grade (12°)


Max Grade (33°)

8,267' 2,520 m


2,672' 815 m



All Clear 40 days ago
Snowy History

Getting forecast...

The Worm Flows Climbing Route is the most direct winter route to the summit of Mount St. Helens.

Napo GV


A Climbing Permit is required per person, per day that you'll be traveling above 4800 ft on the slopes of Mount St. Helens.

This trail is for winter use only when snow covered.
The Worm Flows Climbing Route is the main route to the summit of Mount St. Helens during the winter and early spring. Along the way, you won't find a shortage of steep grades to tackle, but the views from the top and sense of accomplishment you'll glean are worth the effort.
Features: Views
Dogs: No Dogs

Need to Know

While 40 percent of this route is in the trees, roughly 60 percent is in wide open terrain. As such, be sure to bring plenty of sunscreen and protective eyewear to block the reflection of the sun's harmful rays off the snowpack.


Starting at the Marble Mountain Sno-Park parking lot, follow the Swift Ski Trail #244 north through dense forest to pass several junctions with other ski trails. Along the way, be sure to stay off the cross-country ski tracks as you make your way up moderate grades to reach the trail's end at a junction with the Loowit Trail. From here, follow the signs for the Worm Flows Climbing Route.

Once you are above treeline, the trail will follow some wooden posts along one of the lava flows. Eventually, the trail goes onto the rocks, where sometimes you'll see a very marked trail, but not always.

Depending on snowfall, the posts could very well be covered, so be sure to bring a GPS or the Hiking Project mobile app to help keep you on course and off the hazardous glaciers.

Upon reaching the caldera rim, head west to reach the highest point on the volcano and a suite of fantastic panoramic views.

History & Background

Mount St. Helens erupted in a violent plume of ash and volcanic mudslides on May 18, 1980. Since that time, mother nature has done much to restore the vibrant ecosystems once present on the mountain, however evidence of the destructive power of this volcano can still be viewed today.


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Apr 21, 2018
Bala R
6:35 to go up 4:12 to come down 12mi
Apr 13, 2018
Galen Collins
Apr 9, 2018
Kevin L. Young
Nick and I made it to 7600 feet. So close, but we got up at 3 am, left the house at 3:45 and started hiking at 6:45. We turned around at 2:30 9mi — 12h 00m
Mar 24, 2018
Roland Rossano
Mar 15, 2018
Kevin L. Young
Nick and I made it to 6500 feet before turning around 8mi — 9h 30m
Mar 11, 2018
Oleg Ku
Great views on top. Glissading down was awesome!!! 17mi — 8h 25m
Mar 5, 2018
Kevin L. Young
Only made it to the Weather Tower. 155 inches of snow, 5 was fresh powder making it a very hard trek 7.6mi — 9h 00m
Feb 13, 2018
Kevin L. Young
Nick and I made it to the Antenna (weather tower). We are not able to determine exactly how far, but the volunteer said it was 5800 feet — 8h 00m

Trail Ratings

  5.0 from 4 votes


  5.0 from 4 votes
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