Worm Flows, Winter Climbing Route
The Worm Flows Climbing Route is the primary route used by climbers during the winter and early spring to reach Mount St Helens Summit. Worm Flows is the most direct route to the summit of Mount St. Helens during the winter season. Ice axe, crampons, and avalanche awareness are recommended on this route. Skis with climbing skins or snow shoes with cleats are also highly recommended.
From the Marble Mountain Sno-Park use the Swift Ski Trail, #244 to reach timberline. Cross to the west side of Swift Creek, just above Chocolate Falls (elev. 3,700'). Follow ridges and open slopes to the crater rim. Wooden route marking posts guide climbers from timberline to approximately 4,800' elevation. Round trip is approximately 12 miles, Round trip time is approximately 7 to 10 hours. To reduce your exposure to avalanche potential, stay away from snow loaded slopes and gully bottoms. Stay off the cornices at the crater rim.
Climbers should be prepared for winter climbing conditions. Sign in at the register and sign out on your return.
Two websites to help plan your trip are: Northwest Avalance Center West Slopes South and Mountain-Forecast.com.
At a Glance
|Current Conditions:||05/16/2023: Road 83 is passable to all vehicles up to Marble Mountain Sno-Park.
|Reservations:||Between April 1 & Nov. 30 climbing permits are limited in number and purchased online in advance.|
|Permit Info:||Mount St. Helens Climbing Permits are required year-round for each person and each day they will be traveling above 4800 ft elevation on the slopes of Mount St. Helens.
|Best Season:||Winter/Early Spring|
|Busiest Season:||Winter/ Early Spring|
|Restrictions:||Snowmobiles are restricted in the Non-motorized zone, the climbing areas between Monitor Ridge and the Worm Flows.|
|Closest Towns:||Cougar, WA|
|Restroom:||Vault Toilets at Marble Mountain Sno-Park|
From Cougar, WA drive east on Lewis River Road, which turns into Forest Road 90. Continue on Forest Road 90 until the intersection with Forest Road 83. Turn left on Forest Road 83 and continue approximately 6 miles to the Marble Mountain Sno-Park. During the winter and early spring Forest Road 83 is gated at the Sno-Park.
Know Before You Go:
Some Cornices (overhanging snow) on the Crater Rim of Mount St. Helens are unstable and prone to sudden failure. Extreme caution is advised! Do not approach the crater rim unless you can find a wind-scoured area where the surface of the rim is visible. The crater rim is unstable and is subject to frequent rockfall and collapse.
Stay back from the crater edge, it is potentially hazardous at any time of year (especially during the period of elevated avalanche danger and rockfall during the spring thaw).
Winter/early Spring Climbing Tips from a Mountain Steward.
Climbing Preparation and Safety Information
- Climbing Safety
- Climbing Essentials
- Active Volcano Hazards
- Hypothermia/Altitude Sickness
Weekends can be busy.