Why Mount Saint Helens is famous
Before 1980 Mount Saint Helens was a near-perfect snow cone of 2,950 m (9,677 ft), the fifth-highest peak in Washington, with eleven named glaciers and the holiday lodges of Spirit Lake at its northern foot. The eruption of 18 May 1980 is the deadliest and most economically destructive volcanic event in the history of the United States: 57 people were killed, and some 200 homes, 47 bridges, 24 km of railway and 298 km of highway were destroyed. Its summit now stands at 2,549 m (8,363 ft), and the crater left behind is about 1.9 by 2.9 km across and more than 600 m deep.
It is also one of the youngest and the most restless of the major Cascade volcanoes. The cone that existed before 1980 had grown only within the last few thousand years, the mountain has been the most active volcano in the Cascades during the Holocene, and after 1980 it erupted again between 1980 and 1986 and from 2004 to 2008. The US Geological Survey rates it a "very high threat" volcano and watches it with the densest seismic network in the range.
The height keeps changing: a 1982 survey gave 2,549.7 m (8,365 ft) for the high point on the south-western rim, a 2009 lidar survey only 2,539 m (8,330 ft), as rockfalls eat away the rim.
The 1980 eruption and the lateral blast
The mountain woke on 16 March 1980 with a series of small earthquakes. On 27 March steam explosions opened a crater through the summit ice, and over the following weeks magma pushing into the volcano made the north flank bulge outwards by about 1.5–2 m a day; by mid-May it had moved some 140 m.
At 8:32 a.m. on Sunday 18 May a magnitude 5.1 earthquake shook the north slope loose. The whole bulge and summit slid away as a debris avalanche of about 2.5 km³, racing down the North Fork Toutle River for more than 20 km and sending a wave about 180 m high across Spirit Lake. With the lid suddenly removed, the gas-charged magma exploded sideways through the landslide. This lateral blast of hot gas, ash and rock accelerated to at least 480 km/h, perhaps near the speed of sound, and devastated a fan of about 600 km² up to 30 km from the mountain: in the inner zone the forest simply vanished, farther out the trees lay flattened in parallel rows, and at the edge they were left standing but scorched.
Within 15 minutes an eruption cloud rose more than 24 km, and less than an hour after the collapse a Plinian eruption began that lasted nine hours. Winds carried about 540 million tonnes of ash east: Spokane, 400 km away, was plunged into darkness at noon, and the ash circled the Earth in 15 days. Melting snow and ice fed lahars that wrecked bridges and logging camps along the Toutle and Cowlitz rivers and carried sediment into the Columbia River. Because it was a Sunday, few loggers were at work, which kept the death toll far lower than it might have been.
Among those who died were the volcanologist David A. Johnston, watching from an observation post about 10 km north of the summit, whose last radio call was "Vancouver! Vancouver! This is it!", and the 83-year-old lodge owner Harry R. Truman, who refused to leave Spirit Lake and was buried under the avalanche.
Where it is and how to get there
Mount Saint Helens is in Skamania County in south-western Washington, in the western Cascades. Mount Adams stands 55 km to the east, Mount Rainier about 80 km to the north-east and Mount Hood about 100 km to the south-east in Oregon. The nearest international airport is Portland, Oregon. The mountain is surrounded by Gifford Pinchot National Forest, and the national volcanic monument covers about 45,000 ha around it.
The monument has three sides, reached by separate roads:
- West: State Route 504, the Spirit Lake Memorial Highway, leaves Interstate 5 at exit 49 near Castle Rock. It passes the visitor centre at Silver Lake and climbs to Coldwater Lake and the Science and Learning Center at Coldwater, with views of the crater. The road used to end at the Johnston Ridge Observatory, 84 km from Castle Rock, but on 14 May 2023 the South Coldwater debris flow washed out the Spirit Lake Outlet Bridge. The highway has since been closed beyond milepost 45.2; rebuilding of the bridge was announced for 2026, and the Forest Service expects the observatory to reopen in 2027 at the earliest.
- South: from the village of Cougar, 18 km south-south-west of the peak, Forest Roads 90, 83 and 81 lead to the climbing trailheads, the lava tube of Ape Cave and Lava Canyon. This is the side climbers use.
- East: Forest Roads 25 and 99 lead to Windy Ridge, the closest viewpoint open to the public by car, about 6.4 km north-east of the crater above Spirit Lake and its floating mats of logs.
Climbing routes
All summit routes start on the south side. There is no access from the north, which the eruption destroyed, and entering the crater is prohibited.
Monitor Ridge (summer route). The standard route starts at Climbers Bivouac (about 3,700 ft, 1,130 m), the highest point reachable by car, at the end of Forest Road 81-830, with parking and primitive campsites. The Ptarmigan Trail No. 216A climbs 1,100 ft (335 m) in about 3.6 km through forest to timberline at 4,800 ft (1,463 m), where the permit zone begins. Above it the route follows Monitor Ridge steeply through blocky lava, boulder fields and then loose pumice and ash, marked with large wooden posts up to about 7,000 ft (2,130 m); the last 400 m of height are unmarked. The Forest Service gives about 4,500 ft (1,370 m) of gain in 8 km to the rim, and most climbers need 7 to 12 hours for the round trip. It is a non-technical scramble, but the loose ash makes it tiring. When the road to Climbers Bivouac is snowed in (in 2026 it opened on 22 May), climbers must use the winter route.
Worm Flows (winter route). From the Marble Mountain Sno-Park, reached from Cougar by Forest Roads 90 and 83, the Swift Ski Trail and the Worm Flows route climb directly to the summit along lava flows that give the route its name: about 5,700 ft (1,740 m) of gain over roughly 10 km. In winter and spring it is a snow climb with ice axe and crampons; a corridor between the two routes is closed to snowmobiles.
The crater rim. The top is a narrow rim with drops of more than 300 m into the crater, the lava dome and the young Crater Glacier, with Spirit Lake and Mount Rainier beyond. A snow cornice grows over the edge every winter and often lasts well into summer; the Forest Service asks climbers to stay at least 9 m back from the visible edge. In 2008 a snowmobiler fell about 450 m into the crater when a cornice broke and survived, and in 2010 a climber died after falling from the rim.
Without climbing. The Loowit Trail circles the mountain for about 51 km at 1,200–1,500 m, crossing the pumice plain and blast zone on the north side, where camping, fires and leaving the trail are forbidden. Shorter outings include the Hummocks Trail through the avalanche deposit and Ape Cave, a lava tube about 4 km long at a constant 6 °C.
Permits, fees and rules
A climbing permit is required all year for every person, for every day spent above 4,800 ft (1,463 m) on the mountain. As of 2025–2026, according to Recreation.gov and the Forest Service:
- Quota season (1 April – 31 October): permits are sold online on Recreation.gov at USD 20 per climber per day (the fee since 2024), plus a non-refundable USD 6 reservation fee per transaction. The daily limit is 350 climbers from 1 April to 14 May and 110 from 15 May to 31 October. Each month's permits are released at 7:00 a.m. Pacific time on the first day of the previous month.
- Winter (1 November – 31 March): no limit; permits are free and self-issued at the trailhead.
- One permit covers up to 12 people; the holder must be 18 or older, and every climber must carry photo ID and a copy of the permit. Sign the climbers' register at the trailhead before and after the climb.
- Parking at Climbers Bivouac costs USD 5 per vehicle per day or a recreation pass; it is free with a climbing permit displayed. Marble Mountain Sno-Park needs a Washington State Sno-Park permit from 1 December to 31 March.
- Entering the crater, drones and overnight stays without permits for consecutive days are prohibited; human waste must be packed out.
The Forest Service's 2026 route page also lists the 110-climber limit until 30 November, so check the dates when booking. If permits are sold out, the Mount St. Helens Institute runs a limited number of guided summit climbs with permits included. Guides are not required.
When to go and weather
The mountain is climbed all year, but most ascents take place from late spring to early autumn. From July to September the Monitor Ridge route is largely free of snow, though early mornings can be icy and the summit drift may linger; in spring the route is a long snow climb, and from December to March only the Worm Flows route is used. About 3,600 mm of precipitation falls in an average year and the snowpack on the upper slopes can reach almost 5 m; weather changes quickly, and summer heat on the dark, shadeless pumice is a problem of its own.
Water
There is no drinking water on the climbing routes and none at Climbers Bivouac or Marble Mountain Sno-Park. Carry all your water from the start: on a hot summer day of 7–12 hours on dark rock and ash, at least 3 litres per person is a sensible minimum. Snow patches remain in early summer but can only be used if you carry a stove to melt them, and by late summer they may be gone. On the west side, drinking water is available at the Science and Learning Center at Coldwater when it is open.
Mobile coverage and internet
The Forest Service warns that the area is remote and that you may not get a signal even high on the mountain, so a phone must not be your safety plan. Download maps and a GPS track in advance; a satellite messenger adds a margin in winter. The emergency number in the United States is 911.
Dangers and safety
Mount Saint Helens is not a dangerous climb by Cascade standards, but accidents and injuries do occur. According to the Forest Service, most serious ones occur when climbers glissade or slide down snowfields and cannot stop; never glissade without an ice axe. Many climbers get lost on the descent by following the wrong drainage, especially in cloud, because a small detour high up can put you far off route at timberline. Other hazards are the cornice on the rim, icy snowfields with cracks, sudden weather and dehydration.
The volcano itself is a hazard that cannot be forecast precisely. Since 2008 it has been quiet at the surface; earthquake upticks in 2023–2024 stayed within background levels. Check the USGS Cascades Volcano Observatory status, and the avalanche forecast in winter, before you go.
History and name
The Cowlitz people call the mountain Lawetlat'la, roughly "the smoker", and the Klickitat know it as Loowit or Louwala-Clough, "smoking or fire mountain". In the Klickitat legend of the Bridge of the Gods, two brothers who fought over Loowit became Mount Hood and Mount Adams, and she became Mount Saint Helens. About 4,900 ha of the mountain, roughly the area inside the Loowit Trail, are listed on the National Register of Historic Places for their cultural significance.
George Vancouver of the Royal Navy sighted the mountain on 19 May 1792 and named it on 20 October that year after his friend, the British diplomat Alleyne FitzHerbert, Baron St Helens. Settlers witnessed eruptions in the 1840s, during a period of activity that lasted until 1857. The first documented ascent was made on 27 August 1853 by Thomas J. Dryer, the founding editor of The Oregonian, and three companions. Before 1980 climbers used the glaciers of the north side, now gone.
After the eruption the monument was created by Congress in 1982 and the area was left to recover naturally. Climbing reopened in 1987 with a permit system, closed again when the volcano reawakened in 2004 and reopened on 21 July 2006.
Interesting facts
- The eruption released energy equivalent to about 24 megatons of TNT.
- Crater Glacier, which formed in the shade of the crater walls after 1980, is one of the youngest glaciers on Earth; by 2008 its two lobes had joined around the new lava dome.
- The eruption is the most studied in ecology: plants and animals that survived it became the seeds of recovery, and mountain goats, wiped out in 1980, numbered 152 by 2015.
- The mountain's ash was sold as souvenirs and even made into an artificial gemstone, helenite.
FAQ
How high is Mount Saint Helens? 2,549 m (8,363 ft) after the 1980 eruption, which removed about 400 m from the old summit of 2,950 m. A 2009 lidar survey measured the highest point of the rim at 2,539 m (8,330 ft).
How long does it take to climb Mount Saint Helens? Most climbers need 7–12 hours for the round trip on the Monitor Ridge route, about 8 km and 1,370 m (4,500 ft) of gain each way. The winter Worm Flows route is longer, with about 1,740 m (5,700 ft) of gain.
How difficult is the climb? It is a non-technical but strenuous scramble over boulders and loose ash; no rope is needed in summer. In winter and spring it is a snow climb that requires an ice axe, crampons and avalanche awareness.
Do I need a permit and how much does it cost? Yes, above 4,800 ft all year. From 1 April to 31 October permits cost USD 20 per person per day plus a USD 6 booking fee on Recreation.gov, with 350 (spring) or 110 (summer) climbers a day; from November to March they are free and self-issued at the trailhead.
Is there water on the route? No. There is no drinking water on the routes or at the trailheads, so carry at least 3 litres per person on a summer day.
Is there mobile phone coverage? It is unreliable even high on the mountain, and the Forest Service advises not to rely on a phone. Emergency number: 911.
When is the best time to climb Mount Saint Helens? July to September for a mostly snow-free ascent of Monitor Ridge; April to June for a snow climb or ski descent; December to March only for experienced winter climbers via Worm Flows.
Is Johnston Ridge Observatory open? No. State Route 504 has been closed beyond milepost 45.2 since the May 2023 landslide, and the observatory is expected to reopen in 2027 at the earliest. The crater can be seen from the Science and Learning Center at Coldwater and from Windy Ridge.