Mount St Helens Summit in Winter Snow

Trail Guide: Climb Mount St. Helens via the “Worm Flows” Winter Route (12 miles / 5,700′ / 7-12+ hours)

Adventures Trail Guides

Trail details last updated April 2018.

It may not have the steep faces of Mount Hood or the endless glaciers of Mount Rainier but make no mistake, standing atop Mount St. Helens’ summit is a goal well worth of any Pacific Northwester’s bucket list. For most part Mount St. Helens is seen as a summer hike [climbing Helens in summer] with permits for the rocky climb up the Monitor Ridge route selling out in mere days, a true adventure to be sure but in my opinion, that’s not the best way to experience the mountain! If you ask me the best view and certainly the best adventure comes from making the nearly 12 mile, 5,700′ climb along the winter (and spring) snow route known as the Worm Flows.

The Crater Rim at Mount St. Helens with the true summit just to the left (the second hill).

Warning: Alpine mountain climbing is inherently dangerous, even on so called “non-technical” routes. From avalanches to falls, unexpected storms to hypothermia, do not underestimate the mountain no matter what your friends may have told you about that time they did it (hint: it’s not always going to be like that!) Be sure to bring appropriate climbing / snow gear, non-cotton layers, along with food, water and the rest of the essentials. Know the conditions, the route, and the hazards. Have fun but be prepared!


What to expect for your climb

The winter climb of Mount St. Helens is a radical departure from the summer route in just about all respects. Conditions range greatly by year and when exactly you climb as the snow melts away in the Spring but so long as the route is in use, expect to be on snow most if not the entire day. What you encounter can range from resort-like terrain to solid ice, blue-bird skies to freezing whiteouts and it can all change in just a few hundred vertical feet or a few minutes time!

Mount St Helens from Chocolate Falls, Winter Climb

The Worm Flows route of Mount St. Helens is considered class I – II, non technical climb (there are no glaciers or technical faces to ascend if you stay on track) making the mountain a popular entry into the alpine world. That’s not to say the climb is a mere snow hike either however; with a snowpack that easily extends 10, 20, 30′ feet deep (or more), cold days, even colder nights, a winter style (spring counts too!) ascent often requires basic mountaineering tools and skills to ascend and then descend the slopes.

With just about 5,700′ of snow climbing, it’s a long adventure to reach the summit but one that’s filled with amazing views, a fun glissade down, and is a experience no matter how far you get.

FAQ: How long will the climb take? When should I start?

The Forest Service lists the climb at 7-10 hours but I think that’s understating the actual average, especially if you’re a first time climber. From my experience, the summit is usually reached in 5-8 hours with a target of around 6 (1,000′ / hour) while the descent may be up to another 3-4 (2 miles an hour or faster.) Obviously experienced skiers will shave hours of the time down and may be able to skin up faster while experienced climbers can take the ascent down as well. Good glissading conditions and confidence on snow saves some time but don’t expect it to shave off half the day.

Sunrise on Mount St Helens

Throw in a nice summit break, photo stops and enjoying the day and you’re looking at 8-12 hours if you’re walking it. Considering sunset, snow quality, sun exposure and just having a good day out, I strongly suggest leaving between 5 and 6 or even earlier if you’re planning to go on the slow side or if the avalanche forecast is impacted by solar exposure. This may feel incredibly early but think about where the climb + drive time puts you door to door, what warming snow means for climbing up and avy (hint, it’s not fun) and it just makes sense. Camping or car-napping in the sno-park before the climb is incredibly common to snag a few extra hours of sleep.

FAQ: What climbing gear do I need?

While there are plenty of times that a pair of hiking boots and a trekking pole will get you up Helens, there are many days where opposite is true and if you’re new to this, you really won’t know what lies ahead until you’re well on your way to the top. That’s of course because the higher you get, the more consolidated the snow tends to be plus the colder it gets. I’ve had days on the mountain where I passed scores of hikers sitting around hoping for things to completely soften up so they could continue their ascent or just get down; believe me when I say that down climbing an icy slope in bare shoes is not fun.

Crampons for Mount St Helens winter climb

As such it is highly recommended that you come equipped with insulated boots, an ice axe, crampons (microspikes are nice and become more common in spring but they don’t always suffice) and avalanche kit as well as knowing how to use each of them. You may also want to bring your skis & skins if you’re experienced on backcountry terrain or snowshoes in earlier season conditions and after a recent snowfall.

  • For boots pay special attention to the weather rating and look for something that’s ready for the cold (20 degrees or less), waterproof for time in the snow and ideally fairly rigid to allow you to kick in as you go up and down.
  • The primary role of an ice axe on a mountain like Helens is surprisingly not to make for a better summit photo but instead helps to stop a fall (video: self arresting). A straight design, long axe is perfect and will look great in your photos as a bonus.
  • Crampons are used to help walk on solid snow and ice (video: using crampons) and should be tested with your boots in advance of your climb as there are several styles and connection types which may not stay on properly.
  • Avalanche gear makes it easier to be found and to find / rescue someone should you be hit by a slide. Of course understanding the forecast and making smart terrain selection is the foundation to safety so consider an awareness course (video: prep & planning).

I’ve linked videos for each tool to help but watching is not the same as doing so if Helens will be your first time snow climbing be sure to review ahead of time. Even just a little practice the day before your climb or on a long break in the flat section of the route beats having no idea how to arrest if you fall on the upper mountain.

FAQ: What other gear will I need?

Climbing in snow naturally requires more gear than a summer hike and the Forest Service has a list of recommended essentials as does the Mount St. Helens Institute. Both are worth reviewing for specific lists though essentially you’re looking at bringing enough food for a long day (8-10 snacks), plenty of water (3-4+ liters), lots of insulating layers (both warm and waterproof options), your climbing gear, sunblock & good sunglasses, emergency backups, and the rest of the essentials.

Ice axe for mount st helens winter climb

It’s easy to look at the forecast and underestimate the reality of the mountain. Even if the day seems nice, it can be incredibly cold, extremely bright (as the snow reflects) and there are lots of reasons why a trip can drag on. You don’t have to pack for a Himalayan expedition but do plan on bringing a significant pack for the day.

FAQ: What sort of permit is required?

One of the perks of a true winter or early Spring climb is that you get to skip the paid permits and quota system entirely. While a climbing permit is always required, from  November 1st – March 31st, there is no cost attached to them and no advanced registration required, simply head to the Marble Mountain sno-park and sign in at the register to obtain yours.

Winter Climbing Permit

Come April 1st the system changes to paid permits that must be purchased in advance at the Mount St. Helens Institute website. ($22 per climber). For the first few weeks (April 1st – May 15th), a quota of 500 climbers a day is in place and occasionally reached on the final weekends before it runs out. After that, the quota sharply drops to just 100 climbers a day and even spring weekends sells out within a few days if not hours though you can look to repurchase permits at

In addition to climbing permits, each car parked at the sno-park in winter (through April) will need a sno-park pass which you can buy for $20 / day or $40 / season in Cougar. After that a recreation pass (NW Forest Pass, NPS Annual Pass or $5 / day on site fee) are required.

FAQ: Can I camp on the mountain?

Most people attempt the climb in just one day but with dispersed camping allowed below the 4,800′ climbing line, Helens is perfect for a multi-day adventure as well. With the help of a warm sleeping bag and four-season tent, camping out not only makes for fun time but it helps break up some of the work taking over 2 miles and around 1,000′ out of the equation on your summit day.

Snow Camping on St Helens

The most common camping spots are right beyond Chocolate Falls in a flat stretch of the mountain though there are a few secluded spots just before crossing over as well as a little higher on the route. Setting up near (but off of) the trail is common and you’ll almost certainly see at least a couple of tents in the area on a nice day. Just don’t wander too far — camping is prohibited above 4,800′ and there’s no real flat spot on the first ridge near it.

Getting to the trailhead: Directions, lodging, trail facilities

The climb begins at the Marble Mountain Sno-park which is quite simple to find on just about any GPS station though winter conditions can greatly impact the process of actually getting there. Proceed to highway 5, exit in Woodland, WA and then head east on 503 / Lewis River Road for about 45 minutes until you reach the town of Cougar which will lead you right up to the mountain.

Gear for the Climb

Cougar is your last stop for supplies, gas, a warm meal or even for running water before you enter the park in winter. For more extensive purchases or more selection you can find a Safeway, a hardware store and pharmacy in Woodland right off of highway 5 while Amboy (for those coming from the South) has a few restaurants and a local market as well.

After passing through Cougar, continue on Lewis River Road until you reach the marked junction with NF-83 on your left and turn there passing the Ape Caves. Continue to the right at the junction with Climber’s Bivouac (it will be closed just a short way ahead) and continue until the road ends at the sno-park. Depending on the snow conditions, the road can be an easy ride or can require full on winter driving with chains / traction tires. Many people head to Helens for snowmobiling adventures so watch out for large vehicles as you navigate the windy roads of the park.

Marble Mountain is little more than a large parking lot and offers just a couple vault toilets, a small climber registration area to sign into and perhaps the company of a few other climbers. There is no food, water or services around for miles so come ready!

The Climb to Chocolate Falls

With an long climb ahead, it’s typical for people to hit the trail anywhere from the middle of the night up through the early morning depending on their group’s speed and the mode of transportation (skiing back down is a lot faster than walking clearly.) The winter climb is longer and with more elevation gain than the summer route but aside from the flats, it’s consistent and, on a good day, pretty straight forward to make for a solid pace start to finish.

Climbing Route Signs

Departing from the trailhead in the dark, your climb may very well start out on snow or be all dirt for a thousand or more vertical feet as Spring rolls around. In dirt conditions, a pair of trail runners drastically help for the approach while in early season, snowshoes can be a great aid to avoid postholing in the soft snow for the return.

Either way, the trail from the from parking lot to the mountain base is well marked and generally well worn in. While it does intersect with a number of other routes along the way simply staying straight at most of these junctions will keep you on the right track.

Sunrise from Chocolate Falls flats

In total you will hike about 2.5 miles miles and gain about 1,000′, much of which is in the later half of that, before clearing the forest and reaching the mountain base. While a pretty forest, the approach is a complete slog so if you’re new to snow, it’s a good time to dial in your boots and gear, resolve any hotspots and find your rhythm before the steep climb to come.

The route around Chocolate Falls

After a few brief openings, the trail will at last start to open up and you will find the mountain starting to peak through. Exit the dense forest and carefully cross around the cliffs of Chocolate Falls and then up the banks across from you and you’ll find yourself in “The Flats,” a large opening with scattered trees that is fairly flat and usually home to a few tents from groups camping out before the climb. The route up the mountain lies dead ahead with marker posts visible as the snow melts down (look for the rocky ridge just to your right if you don’t see those.)

The Climb to the Weather Station

After making the short walk over the flats you’ll notice the terrain starts to pick up quickly as you approach the ridges that will lead you up the mountain. Even with a deep snowpack there are often bands or rock visible along the first stretch of the climb (these may continue on up or be all buried depending on the season / timing) offering your first navigation challenge. The official route is along the rocks though they can be tricky to handle with melting snow so many climbers elect to skirt the edge of the gully to the left instead, at least when it’s free of cornices that is (be extra careful in gullies if there is any avalanche risk.)

First Ridge of the Climb

Follow the ridge on up whatever way feels best through what is often the most annoying part of the climb taking it left towards the hills above. If things are still snow covered, this cut to the left will be one of the more exposed parts of the climb and is about as steep as most anything that lies ahead of you. I’d be lying if I said I had not made the climb harder then it should have been ascending in the pre-dawn darkness once or twice so I seriously mean this when I say it: nothing in the first half of the day should be steep enough to pose a real challenge, if it is, check your route!

Worms Flow Route First Ridge

While this ridge is low on the mountain it does offer up some incredible views of the forest, Mount Hood and the slopes below as you ascend on up.

Once you rise over the first hill you should catch a glimpse of the weather station above you and you’ll likely start to see tracks going in different directions as people look for their own best way up the mountain though within a relatively close proximity. Climb up a couple of smaller rises until you see the steeper face below the weather station and either directly ascend it or go around to the right to skip it all together. Either way you will find a nice flat area to take a break and make it a long one as you’ve passed the half way point on the climb.

The Climb to the Swift / Monitor Ridge Meetup

Departing the weather station area you may be more than half way to the top but don’t expect things to get easier, in fact, they’ll just get steeper. You’ll also find that the rolling slopes of the mountain obscure the view above so take in the route as best you can before you continue ahead (there is a false summit on the normal route so know that what you’re looking at for the last bit of the climb isn’t really the end.)

The upper slopes of Helens, winter climb

As you continue on up you’ll switch between more notable slopes and more gradual ones a few times which is what creates the false summit effect. There are two fairly flat spots along the way that serve as good targets to move between for your next breaks and I highly encourage using them for real pauses rather than constantly stopping all the time. Micro-breaks just don’t have the same effect for rest and really slow you down.

The Final Push to the Summit

As you pass above 7,000′ you’ll notice that you’re getting awfully close and also that there’s a ridge dividing the mountain.

On the left is a the transition over to Monitor Ridge and though what you can see is a false summit (the actual crater rim lies a few hundred vertical feet beyond it), it is the “actual” route up the mountain. Slightly to the right is the Swift Glacier which leads more directly to the rim though it can be anywhere from steeper to super steep.

Worms Flow to Monitor Ridge Summit

In the snowy season routes are far more about the conditions of the day than what’s on a map and there are times when it may be difficult to get over to Monitor Ridge or fairly straight forward to get up the Swift which is a more direct way to the crater rim (though there are times when it’s really not climbable too.) It is typical for people to follow the established boot path up though there are also days where you have groups splitting up and going both ways too.

The final push up Helens

If there’s a clear way over to Monitor Ridge that’s usually the best bet but ask, it’s always good to know what others have faced as they make their way down.

Success: You’ve reached the Crater Rim!

After cresting up to Monitor Ridge, realizing I wasn’t kidding about the false summit, and making your way up the last few hundred feet you’ll know you’re at the top when there’s nothing higher above you.

Dead ahead will be Mount Rainier well in the distance with Spirit Lake appearing below it, the building at Johnston Ridge is even visible as a small line if you look closely. Mount Adams is off to your right and Mount Hood / Jefferson / The Sisters are behind you (in order.) If you’re aiming for the true summit, look to your left, it’s a few minutes walk over (cut down to the lower slope if you do want to try for it.)

Mount St Helens Summit in Winter, Worms Flow Route

Before you go running to the edge for a photo however it’s really important to remember the cornice. Essentially a cornice is snow that has built up on its self and which hangs freely over the air below it. On the crater rim that means it’s essentially hanging over an abyss and just waiting to fall off into it so obviously you want to stay off that which may means well back from the edge!

This is a cornice!

On a nice day, the summit is a wonderful place to have lunch and enjoy a long break though on a windy day it can be absolutely freezing too, it just depends on the conditions you end up with. If it’s nice and early in the day, you may find skiers hanging around while they wait for the snow to soften up and that means easier glissading too, it’s hard to beat lying out in the sun with the view!

Descending the Mountain & Glissading

I usually simply describe the return down a mountain route as reversing the way you came up with appropriate caution but snow climbing introduces a different set of issues that many don’t consider in advance. Since Helens is so often used as a first alpine climb, I’ve decided to elaborate on going down as it’s not always as easy as you’d think.

Looking down the mountain

The first real issue I see people run into is frozen snow. While it’s hard to move any direction on solid snow and especially ice, it’s generally possible to keep heading up by finding the occasional soft spot and / or leaning into the mountain. On the way down this is far more of an issue however as it really just takes one bad step to go sliding (and if things are icy, to keep sliding). The solution is either to wait for the snow to soften up in the sun on a nice day or you know, use those crampons you lugged up to dig on (contact with your heel to hold your weight.) An ice axe is a very useful tool for helping if you do fall though in a pinch your trekking poles work too.

Even on a great day it’s still totally possible to get freaked out by the steepness heading back down. This is of course more in your head than anything else and the best way out is to get moving. Plunge step into the snow and let yourself sink in and you’ll fly on down rather than trying to catch each step with your toes.

Glissading down Mount St Helens

And of course there’s glissading aka butt sliding down down the mountain. Obviously this is a blast but there are some things to know before you just start sliding on down.

  • Be sure the snow is suitable to glissade on: icy or firm snow will not work well and can lead to an uncontrolled slide.
  • Remove any crampons or microspikes from your shoes as they can catch a rock or piece ice and send you spinning around or impale someone else.
  • Also be sure you have a way to slow or stop your descent using a trekking pole or ice axe as a hand break and digging your boots in as your primary stop.

Finally, be sure to consider your glissade route. Just because you see a used path does not mean it’s free from rocks, gaps in the snow, or other hazards nor does it mean that it will go where you want to end up. Scout each section briefly before you start sliding on down and when you’re ready, well, have a blast!

Quick facts about the trail:

  • Route: The Worm Flows via Marble Mountain Sno-park
  • Official Rating: Very Difficult
  • Start point: Marble Mountain Sno Park
  • Distance: ~12 miles round trip
  • Duration: likely 8-11 hours (without skis)
  • Climb: ~5700′ gain
  • Facilities: Vault restrooms at the trailhead
  • Water: None at the TH or on the trail
  • Crowds: Light to moderate based on weather
  • Cost: Washington sno-park permit Nov – April / NW Forest Pass otherwise
  • Permits: Advance purchase only April 1 – Oct 31 (self-issued & free off season)

Additional Reading: