Robert and Barbara Decker

Maps and Drawings by Rick Hazlett

Copyright 1993

ISBN: 0-9621019-6-6

Print copies of this booklet may obtained from the publisher: Double Decker Press; 4087 Silver Bar Road, Mariposa, CA 95338. Put on the web with the permission of the copyright owners and publisher.

Illustrations relative to active volcanism are included as links. Other illustrations in the print text are not included in this web page. Links to illustrations not refered to in the print text are marked with a bullet. Text references to omitted illustrations have been deleted from this web page.






Welcome to Mount St. Helens National Volcanic Monument. This book is designed to guide visitors on a driving tour of the major sights in this land of volcanic destruction and dramatic biological renewal. It is planned for the reader who has about two days for a visit, with the first day a drive up the new Spirit Lake Memorial Highway, a spectacular 50-mile-long road leading to the Coldwater Ridge Visitor Center and a close-up view into the heart of the shattered volcano.

The second day includes a drive to the north and east sides of the Monument, through miles of forest destroyed by the eruption of Mount St. Helens on May 18, 1980, with views of Spirit Lake and many fine examples of Nature's process of recovery - perhaps even a glimpse of one of the returning elk herds.

For those who can spend more than two days in this intriguing national monument we include a section about the south side, an area comparatively untouched by the 1980 eruption but with volcanic features that give important clues to Mount St. Helens' past -- and possibly her future. You will also find hiking trails of varying difficulty listed on page 43.

Besides recounting the geologic story of Mount St. Helens and its infamous 1980 eruption, this book tells something of the monument's trees, flowers and wildlife -- especially their response to catastrophe. But space is limited and there is much more to be said; for those who have a special interest in any of these topics we include a list of suggested reading with more detailed information.


The starting points for Day 1 and Day 2 are starred on the Map of the Mount St. Helens Region. (325K) The following symbols in the text indicate major points of interest:

OUT = Stop in the parking area, climb out of the car and look around.

HIKE = Stop in the parking area and take the suggested short walk.

LOOK = Things to notice from the car while driving between stops.

The number following the symbol shows the total miles driven. For example, (7.8) means that your mileage indicator should show that it is 7.8 miles since you started your guided tour.

The second day's drive is a long one, so try to get an early start. There are no overnight accommodations in the monument and no gas stations, so have a full gas tank when you start out; meals and snacks are available at a few locations. If you are visiting Mount St. Helens in the winter you will probably find the roads listed for Day 2 closed by snow between November and May; check at the Visitor Center. The Spirit Lake Memorial Highway, however, will be kept open all year.


The eruption and recovery of Mount St. Helens is a story of death and life; destruction and creation. In March 1980, the volcano awoke from 123 years of sleep. Two months later it destroyed itself in a giant avalanche and explosion. In a matter of minutes Mount St. Helens changed from a graceful cone to a blasted stump. The devastation was sudden and catastrophic, but the recovery taking place in the years that have followed has been almost as dramatic.

The area devastated by the eruption is so large that the story is best told in pieces as you travel around the volcano and see the actual destruction and recovery. However, a framework in which to fit the pieces is needed, and this introduction is a brief summary of the major events of the eruption and healing of Mount St. Helens.

Earthquakes and small explosive eruptions signaled the awakening of the volcano. The first quake jarred the mountain on March 20. Many more followed, in an earthquake swarm that put the Forest Service and geologists on alert that something highly unusual was happening. Five days later a booming steam explosion from the summit of Mount St. Helens announced the first volcanic eruption in the Cascade Range in more than 60 years.

Cracks and craters formed in Mount St. Helens' icy summit, and intermittent steam and ash explosions blackened the snow-clad cone. No new magma -- molten rock from deep inside the earth -- was evident in the ash particles from these relatively small eruptions, but the continuing earthquakes and steam explosions from heated ground water indicated that magma was rising beneath the mountain.

The earthquakes were occurring at depths about 1 to 2 miles beneath the high north slope of Mount St. Helens. Measurements soon confirmed what observers thought they could see on the volcano: a huge bulge was growing upward and outward...

on the north face of the cone. More than a mile in diameter, the ominous bulge had pushed out 300 feet by mid-April and was growing at a rate of 5 feet per day.

The small eruptions stopped, started, and stopped again, but the quakes continued. On May 18 geologist Dave Johnston's early morning measurements and radio report from a high ridge 5.5 miles from the volcano indicated that the bulge continued swelling at a steady rate. An hour later Dave was dead. At 8:32 AM a magnitude 5.1 earthquake shook Mount St. Helens and triggered the giant avalanche of the bulging north slope of the cone. That was like opening the lid on a huge, overheated pressure cooker. As the avalanche slid away into Spirit Lake, the weight and the pressure of the mountain overlying the heated ground water and shallow magma were suddenly reduced. Hot water flashed to steam, and gases in the magma boiled out with great violence.

The blast cloud shot out the torn-open north face and quickly outraced the speeding avalanche. The cloud was so loaded with hot rock fragments that it hugged the ground, racing north, northwest, and northeast. It climbed ridges and swept down valleys; a hot dense cloud that blew trees down like toothpicks, destroying 230 square miles of forest, and killing almost everything in its path. The sequence of events from the triggering...

earthquake through the entire blowdown took only five minutes.

The unroofed magma column continued to jet upward for the next nine hours into a 15 mile high ash cloud. It was like a giant rocket buried nose down. More dense portions of the ash cloud near its base formed pyroclastic flows of hot rock frag ments fluidized by expanding gas. These flows poured out of the breech of the horse shoe-shaped crater toward Spirit Lake, covering part of the avalanche deposits.

Mudflows -- floods of water from melting ice, the ground water soaked avalanche, and perhaps the slosh of Spirit Lake, laden with ash and soil -- rushed down the streams and rivers around Mount St. Helens. Homes and bridges were swept away. Much of the mud finally came to rest in the Columbia River where it clogged the navigation channel for months.

The gigantic eruption was much larger than anticipated, mainly because the north face avalanche suddenly released the pent up volcanic energy. Fifty-seven people died, property damage totaled 1.5 billion dollars, and the perception of volcanoes by the residents of Washington and Oregon was dramatically changed from serenity to violence.

Human history and natural history are both a series of sudden revolutions followed by slow evolutions. The eruption of Mount St. Helens was a sudden, drastic revolution that profoundly changed the volcano and its surroundings. Now, evolution is slowly rebuilding the mountain and forest. The huge explosion is history. Today's story, and that of the next hundred years, is the story of Mount St. Helens' recovery.

In recent years the most common image of volcanic destruction has been the sight of a Hawaiian lava flow moving slowly over a landscape, engulfing everything in its path and sealing the land under a layer of glistening black rock. There recovery can only come by colonization from the outside, at speeds that depend largely on the amount of rainfall, and in a usual sequence of algae and lichens followed by mosses and ferns and eventually woody plants.

At Mount St. Helens, though, since the volcano's devastation came in many forms, biological recovery is taking place not in predictable textbook fashion but with complicated, fascinating interconnections. The pace and sequence of recovery is different in the blast zone, on avalanche and mudflow deposits, in areas of heavy ashfall, and on pyroclastic flow deposits (the closest analogy to a lava flow with respect to high temperature). Every place except on the pyroclastic flows, recovery has probably depended more on survivors than on colonizers.

Even in the blast zone where the land looked as if it had been scoured and sterilized, surprising evidence of surviving life started to emerge in the first weeks after the eruption. Nothing on the surface could have lived, of course, but under the ground roots of dormant plants, colonies of ants, and some small animals like pocket gophers and deer mice were able to escape the holocaust going on overhead.

The time of year -- mid-spring -- was an important factor in survival for some plants. Late snowbanks sheltered small trees and other plants, leaving islands of living foliage when the snows melted. Spring rains carried away some of the ash, and in those erosion gullies more plants were waiting to sprout.

The interactions of colonizers and survivors proved to be one of the more intriguing stories. Naturalist John Muir observed in 1869 that "When we try to pick out anything by itself, we find it hitched to everything else in the universe." Nowhere is this more evident than at Mount St. Helens. A lupine or huckleberry plant...

sprouting from a buried root might hold moisture and attract insects, as well as catching blowing seeds of weedy plants like fireweed or pearly everlasting, giving them a chance to take root. Birds looking for moisture and insects among the new plants might leave droppings that would provide not only fertilizer but other seeds. In this way tiny islands of life started that grew and provided shelter for more plants and small animals, and eventually food for larger browsing animals.

As pocket gophers tunneled underground looking for tender roots and bulbs they threw dirt out of their burrows, bringing to the surface the organic soil and fungi from beneath the ash. Gopher mounds, so dreaded by gardeners, were oases for wind borne seeds, and new colonies began.

Large animals -- elk and deer -- came to browse on the new vegetation; their hooves broke up the hard crust of the ash and left deep footprints where more seeds could collect and start other plant colonies. By 1983, 90% of the plant species origi nally growing at Mount St. Helens could be found, though numbers and dominant species varied widely with location.

Of all the birds and mammals that were in the forest on May 18 only those in the margins of the blast area survived, but their return to Mount St. Helens has been remarkable also. Birds were flying into the blast zone almost as soon as the ash settled, though most nesting sites were gone. Animals -- large and small -- that could fairly easily change their habits and diets were finding their way back sooner than anyone expected. It had been feared by some that the destruction of Roosevelt elk and black tailed deer would affect the population for many years, but that has not proved to be the case. For the estimated 1,500 elk and 5,000 deer who were in the wrong place in May 1980 it was a catastrophe; for the species it was not.

After 5 years the numbers of elk and deer at Mount St. Helens were back to normal.

The forests around the mountain were some of the most beautiful in the northwest, with Douglas-fir, western red cedar, western hemlock and noble fir, mixed with red alder, maple and cottonwood. At higher elevations Pacific silver fir, subalpine pine and a few other hardy varieties flourished. Almost all were blown down or shattered to matchsticks in a matter of minutes. Now forest recovery is starting, but it is taking place in two distinctly different ways.

The land outside the National Monument boundaries, some managed by the Forest Service and some by private companies, is undergoing an aggressive reforestation program. The Forest Service alone salvaged 200 million board feet of downed and standing dead trees, and has replanted millions of small trees.

Inside the monument boundaries 110,000 acres have been set aside to study Nature's intricate process of healing itself. Besides the interaction of colonizers and survivors, the speed and direction of recovery will depend on two notoriously fickle elements -- the prevailing weather, and future volcanic activity. Barring too many surprises, educated guesses are that in 50 years a healthy young conifer forest will be growing -- a mature forest could develop in 100 years -- and in 200 years it could look like other old-growth forests of the northwest.

Out of the devastation at Mount St. Helens has come an almost unprecedented scientific opportunity; the eruption left more than 200 square miles as clean a slate as scientists are likely to find. Researchers from all over the world have come here to conduct experiments -- some lasting for many years -- on the recovery of a severely damaged eco system. A common theme that emerges in the thousands of research papers has been amazement at Nature's resilience.

Geologists who read Mount St. Helens' battle scars know that this cycle of destruction and renewal has been repeated many times in the last 40,000 years, and there is certainly no reason to think that it won't be again. Mankind can profoundly affect the environment for better or worse, but as the saying goes, Nature always bats last.


The best place to start your tour is at the Mount St. Helens Visitor Center, five miles east of Interstate 5 on State Highway 504. This used to be the main route to Spirit Lake and Mount St. Helens, but much of that road was buried beneath the avalanche and mudflows of the great 1980 eruption. Its replacement is now known as the Spirit Lake Memorial Highway. Constructed during 1992-1995, it is a spectacular road high above the valley of the North Fork of the Toutle River, leading to Johnston Ridge and an unforgettable view into the huge crater of the volcano.

Mount St. Helens Visitor Center

HIKE (0.0) Mount St. Helens National Volcanic Monument, administered by the Forest Service, was established in 1982 to encourage research, education, interpretation, and recreation on the volcano. The handsome Visitor Center of large timber and stone construction blends perfectly with its setting of...

old-growth conifer forest. Even though it is still 40 miles to the actual monument boundary, the Mount St. Helens experience begins here.

Take time to see the audio-visual shows in the theater and enjoy the excellent exhibits on volcanoes of the world, the Cascade volcanoes, and of course Mount St. Helens. A long look at the topographic model will give you a bird's eye view of today's trip, tomorrow's east side excursion, and features on the south flank of the volcano.

On clear days you can see the real Mount St. Helens, 30 miles away across Silver Lake, from the terrace in front of the Visitor Center. The short trail that circles the building provides an easy walk before your road trip. Set your trip meter to zero or note your mileage indicator, and turn right on Route 504. The next stop will be in 21.5 miles.

LOOK At (2.9) miles the road skirts the north arm of Silver Lake, choked here by invasive water plants. The lake was created when a prehistoric mudflow from Mount St. Helens dammed one of the Toutle River's tributary streams.

At (5.6) miles a new bridge spans the Toutle River, replacing the one that was swept away by the late afternoon mudflow on May 18, 1980. Along here the mudflow was moving at only about 3 miles per hour, but it carried hundreds of logs from a lumber camp upstream that acted as battering rams against the bridge.

Across the river at (14.4) miles, banks cut into prehistoric mudflows expose rounded boulders that are loosely cemented by dried mud. This is just one of many clues to the volcano's past; layer upon layer of mudflows like this show that Mount St. Helens has had a long -- and continuing -- eruptive history.

Look downhill to your left at (15.6) miles. The group of buildings beside the North Fork of the Toutle River is a fish collecting facility, where migrating steelhead and coho salmon are picked up and carried around the dam upstream. This river and its tributaries had been their home and spawning ground, but in 1980 the habitat was suddenly and drastically changed. Not only did volcanic ash and debris choke the river and streams but muddy water stifled the growth of algae on stream bottoms, disrupting the food chain.

In the life cycle of steelhead and coho salmon, the first year is spent in streams and then two to four years in the ocean, after which they return to their home streams to spawn. Fish returning to the Cowlitz and Toutle rivers that spring found the waters to be intolerably turbid and silt filled, so they turned to other Columbia River tributaries instead.

Since then the streams have become more clear and hospitable every year, but a new obstacle for migrating fish has come in the form of the sediment dam and spillway built just upstream from here in 1986-1989. To ensure the fish safe passage to their spawning grounds this fish lift was established. The fish coming up the river are trapped here, loaded into tank trucks, and transported to a release point above the dam. In the future this facility may be opened to the public so visitors can watch the fish collection taking place.

The area where the fish traps are now was covered by a large mudflow seven hours after the 1980 eruption began. The thick flood, described by witnesses as having the consistency of warm concrete, reached heights of 20 to 30 feet above normal river level. Much of the flood water apparently originated from the water-soaked avalanche debris up the valley, squeezed out as the deposit compacted. The crest of the mudflow moved on downstream destroying about...

200 homes, carrying some away and burying others. It crested at Castle Rock on the Cowlitz River about midnight, 30 feet high and 85 degrees F warm. Moving on down into the Columbia River the mud settled into the shipping channel, reducing its depth from 40 to 15 feet. Ocean ship traffic to and from Portland was disrupted; it took six months of dredging before shipping was fully restored.

Upstream from the fish traps is the large sediment dam and spillway built by U.S. Army Corps of Engineers to control floods and mudflows that are expected to course down the North Fork for many years. The dam is 184 feet high, 1,800 feet across, and can retain some 260 million cubic yards of sediment before the basin behind the dam is filled -- probably in about the year 2035.

The forests along the highway beyond the fish lift have been planted by lumber companies on private lands. Douglas-fir at this elevation grow to about 20 feet tall in 15 years. A typical managed forest is hand planted with seedlings, thinned at 10-15 years and 25-35 years, and matures in about 50 years. These plantings were not affected by the eruption, and examples of nearly all stages of commercial management can be seen.

Hoffstadt Viewpoint

OUT (21.5) Turn right into the parking area. This viewpoint provides a fine vista of Mount St. Helens, 15 miles to the southeast. Also visible, 1.5 miles distant in the same direction, are remains of the first sediment dam built across the Toutle River Valley to impede the runoff of loose ash and avalanche debris during winter storms. Built in 1980, it was filled and overtopped by mudflows in 1981-1982.

Mudflows occur during an eruption if a large source of water is involved. An eruption that throws out a crater lake or melts an icecap can produce extremely large mudflows. In 1986 a relatively small eruption from Ruiz Volcano in Colombia...

melted just a part of its icecap, and the resulting mudflows killed 25,000 people in towns surrounding the mountain.

A mudflow can happen even without an eruption taking place. When ash, weak rocks, or thick soils are loosened by heavy rains, rapid snow melt, earthquakes, or some combination of these events, a devastating mudflow can result. During the next few decades the loose ash and avalanche deposits near Mount St. Helens make the streams and rivers draining this area particularly hazardous.

The road ahead has some long, steep grades. If you are pulling a trailer you may want to leave it here in a special area of the Hoffstadt Viewpoint parking lot that has been set aside for that purpose. The next stop will be in 6.6 miles.

LOOK The hills and cliffs on the left side of the Highway are called Hoffstadt Bluffs, and are eroded remnants of rocks from an earlier period of volcanic activity that occurred millions of years ago.

At (24.4) miles the road crosses Hoffstadt Creek Bridge, 2,340 feet long and 370 feet above the creek; it cost 13 million dollars to build. Trees in this area were killed but not blown down by the huge 1980 explosion; their needles were fatally scorched by the waning blast. The trees you see now were planted after the eruption. The mountain ahead, North Fork Ridge, tops 3,200 feet in elevation.

North Fork Ridge

HIKE (28.1) Turn right into the parking area. About a mile back you entered the area where all the trees were blown down by the giant eruption blast. The source of the explosion, Mount St. Helens, is 14 miles away. James Scymanky and three other loggers were felling timber about a half mile north of here that morning, with Mount St. Helens hidden by the ridge. In Scymanky's words. "..a horrible crashing, crunching, grinding sound..." immediately preceded the arrival of the blast cloud. Then Scymanky was knocked down. He could see nothing, but recalls the searing heat, darkness, and near impossibility of breathing that lasted about 2 minutes. When visibility returned, all the trees were down and thick gray ash covered the devastation. All four men were badly burned, and Scymanky's three companions later died.

After 1980, the blown-down timber in this area was salvaged for lumber and new trees were planted. Holes had...

to be drilled with a power auger down through the ash layer into the underlying soil. Seedling trees were then planted in the soil-ash mixture. As you can see, the young trees seem to like their new habitat.

Walk up the small hill at the south end of the parking lot for an impressive view. The huge avalanche that triggered the eruption of Mount St. Helens swept down the North Fork of the Toutle River into the valley below this overlook. Here, most of the surface of the avalanche has been eroded and redeposited by floods and mudflows since the eruption, but upstream large areas of the original hummocky avalanche surface are still evident.

As you walk back to your car, notice the rocks in the road cut across the highway. These old eroded volcanic formations provide a glimpse of what lies beneath the present active volcanoes of the Cascade Range.

The next stop will be in 4.0 miles.

LOOK At (29.6) miles, the high ridge ahead is Elk Rock, 4,391 feet above sea level. The horizontal scars on the high slopes are old logging roads. Campers on Elk Rock were killed by the 1980 blast.

Elk Rock

OUT (32.1) Pull into the parking area on the right. The panorama from this viewpoint is spectacular (see pages 20-21 Panorama from Elk Rock (156K)); it's even better through binoculars. From north to south along the horizon: Black Mountain, 8 miles distant, just beyond the blast zone and covered by forest; Mount Venus, 9 miles away, its right half within the blast zone; Mount Whittier and the alpine ridge connecting it to Mount Margaret, 10 miles distant, well within the blast zone; Harry's Ridge with Mount Adams, 41 miles away, rising behind it; Johnston Ridge, 6 miles distant; Windy Ridge, 10 miles distant, just beyond Spirit Lake which is hidden behind Harry's and Johnston Ridges; Mount St. Helens, once 9,677 feet high, now reduced to 8,365; and Spud Mountain, 3 miles to the south, whose summit divides the blow-down zone (east side) and the singed-zone (west side). Spud Mountain is outside the monument and its dead trees were salvaged.

Below the horizon other features can be seen from here: the valley on the north side of Mount St. Helens is buried by 600 feet of avalanche debris that in turn was covered by more than 100 feet of pyroclastic flow deposits -- the pumice plain. The avalanche raced toward this viewpoint and swept on down the valley for 5 more miles...

west of Elk Rock. The original avalanche surface is covered with hundreds of hummocks 20 to 100 feet high, but stream erosion and deposition is rapidly smoothing its surface into wide, flat-bottomed canyons with steep banks.

Look down into the canyon and you might be lucky enough to see some of the Roosevelt elk that have returned in large numbers. They usually travel in herds, and like to browse on the new vegetation growing up along the meandering streams. The next stop will be in 3.6 miles.

Castle Lake Overlook

OUT (35.7) Pull into the parking area on the right. The view from here is dominated by the 1980 avalanche debris. Castle Lake, across the valley, was created when Castle Creek was dammed by the thick avalanche deposits. Large landslide dammed lakes like this are dangerous because if they overflow the outlet channel may quickly erode, draining the lake in a sudden catastrophic flood.

Few people have ever witnessed the start of a huge avalanche, but by coincidence -- or geologists' luck -- two people saw this one begin. Geologists Keith and Dorothy Stoffel were flying over Mount St. Helens in a small plane at the instant that the magnitude 5.1 earthquake beneath the mountain struck. The quake was the last straw for the oversteepened bulge that had been growing on the north flank of the volcano; about 15 seconds after it began, a series of giant blocks began to slide from the north face of Mount St. Helens. In Dorothy's words "The whole north side of the summit crater began to move instantaneously as one gigantic mass...(it) began to ripple and churn...then the whole north side of the summit started moving to the north..."

The avalanche reached speeds as high as 170 mph near the base of Mount St. Helens, but slowed coming down the less steep valley of the North Fork. Its 15-mile plunge down the valley below you took an estimated 10 minutes. The avalanche was the largest ever recorded in history; it consisted of nearly 0.7 cubic mile of rock, ice, soil and trees. No one saw it sweep down the valley -- the explosion cloud triggered...

by the avalanche outraced the slide and hid all but the first minute of collapse.

Notice the ponds on the surface of the hummocky deposit where it has not been smoothed by mudflows. Some of these depressions formed as large glacial ice blocks in the avalanche slowly melted away, letting the ground above them sink.

The next stop will be in 2.9 miles.

Coldwater Ridge Visitor Center

HIKE (38.6) This major visitor center focuses on the recovery of Mount St. Helens -- how Nature heals her wounds. Besides seeing the excellent exhibits, be sure to allow enough time here to walk the 1/3 mile-long Winds of Change Interpretive Trail.

Coldwater Lake, below the ridge, is another example of a lake formed by avalanche damming, this time of Coldwater Creek. In the early 1980's timber in the blast area around the lake was salvaged, and tug boats hauled log rafts along this lake. A boat ramp, fishing dock, interpretive trails and picnic facilities will be available for visitors at Coldwater Lake.

Until the road is completed in the summer of 1995, this is the end of the Spirit Lake Memorial Highway. After that the road will continue to Johnston Ridge, and the next stop will be in about 6 miles.

Spirit Lake Tunnel

OUT (45) To prevent the overflowing of Spirit Lake and to keep it at a stable level the Army Corps of Engineers bored a 1.6-mile-long tunnel beneath Harry's Ridge to the lake. During 1982, Spirit Lake came close to overflowing its dam of loose debris left by the 1980 avalanche. That could have led to a catastrophic flood and mudflow down the North Fork of the Toutle River. Emergency pumps were installed on the lake and used to control its level until the tunnel was completed in 1985.

The next stop will be in about 3 miles.

Johnston Ridge

HIKE (48) David Johnston, the geologist who made the last measurements of the bulging north flank of Mount St. Helens, was killed here by the huge volcanic blast of May 18, 1980. This spot is 5.5 miles from the crater, and was 1,200 feet above the river valley before the avalanche; it was chosen for a pre-eruption observation post because the area had been cleared by logging and provided an unobstructed view of the mountain. David's last radio transmission from here at 8:33 AM that fateful morning was "Vancouver, Vancouver, this is it!" Then silence.

A ham radio observer named Gerry Martin, two miles north of here on Coldwater Divide, also watched the huge avalanche and explosion. His last transmission was "The camper and the car just over to the south of me (Dave Johnston's observation post) are covered. It's going to hit me too."

After the initial giant blast to the north from Mount St. Helens, the eruption continued for the next nine hours jetting volcanic ash into a huge vertical column that was blown eastward by the prevailing winds. The gases boiling out of the uncorked volcano provided the energy for this continuing eruption. During the afternoon pyroclastic flows spilled out of the open north side of the crater beneath the jetting ash column.

A pyroclastic (pyro means fire; clastic means broken) flow is the most dangerous and most misunderstood of all volcanic features. It consists of a hot, denser-than air mixture of rock fragments and gases -- principally steam, carbon dioxide, and heated air. This emulsion of solid particles and turbulent gases acts like a fluid, so a pyroclastic flow can pour down a steep slope at speeds exceeding 100 mph. An ash cloud rises from an onrushing pyroclastic flow, making its progress look as if an explosion vent were ripping down the volcano's side. About 20 pyroclastic flows swept out of Mount St. Helens' crater during the afternoon of May 18, building up a plain of pumice deposits on top of the avalanche debris. The pumice lumps are fragments of solidified volcanic froth, like the foamy head on beer if it were fast frozen. Frozen beer foam would be tiny gas bubbles surrounded by ice; pumice is tiny gas bubbles surrounded by solidified volcanic glass. Erupting pyroclastic flows are hot, as high as 700 degrees C (1300 degrees F). When they hit water, steam explosions blast craters into the pyroclastic deposits. Many of these secondary explosions happened when pyroclastic flows swept into Spirit Lake or onto wet avalanche debris. Delayed steam explosions, days or even months after the pyroclastic flows took place, occurred here on the pumice plain. This happened when water that had been covered by the hot pyroclastic flows was slowly heated to the point where the high pressure steam could burst through the covering layers.

Pyroclastic flows are often mistakenly referred to as lava flows, which are masses of viscous molten rock and move much more slowly. The dome that nests within the crater at Mount St. Helens is made up of lava so viscous that when it erupts it piles up over the vent instead of flowing away. It has grown in pulses; small domes of thick lava that squeezed out of the top of the magma conduit during the summer of 1980 were blown out by explosive eruptions in July, August, and October of that year. These explosions were much smaller than the original eruption but they generated impressive ash clouds, and some small pyroclastic flows that poured down on the pumice plain.

Between late 1980 and 1986 the lava dome grew in 16 relatively quiet eruptions that were not followed by destructive explosions. By 1992 the dome was about 1,000 feet high and 3,000 feet wide. These numbers don't do it justice; comparisons are better. Imagine the Washington Monument placed in the crater; it would only be half as high as the lava dome, and would look like a matchstick from here. The nearly 1-mile-wide, 2-mile-long, 2,000-foot deep crater is so large it makes the dome seem small.

As of 1992, no new pulses of lava growth had affected the dome since 1986. However, 28 very small explosions from the dome -- possibly caused by heated ground water -- were documented during 1989 to 1991.

Will more eruptions occur at Mount St. Helens? The answer is yes. The tougher question is when. The cessation of dome growth in 1986 suggests that the recent period of activity may be over. On the other hand, in the first half of the 19th century and in prehistoric times eruptive periods of Mount St. Helens are known to have lasted for many decades. History, including geologic history, tends to repeat itself. The answer to the question of when the next eruption will occur is "Let's wait and see."

This is the last stop of today's trip -- if you didn't take time to look around the Mount St. Helens or the Coldwater Ridge Visitor Centers you may want to spend some time in one of them on the way back. The second day's trip to the east side of the monument starts at the junction of Roads 25 and 26 (see maps on pages 2-3 Map of the Mount St. Helens Region. (325K) and 25 Northeast Side Map (104K)). Try to get an early start -- there's a lot to see.



Mount St Helens: Named by George Vancouver in 1792 for Baron St Helens, an English nobleman
Elevation: 1979 9,677 feet in 1979; 8,365 after 1980 eruption
First eruption in 20th Century: March 27, 1980
Great eruption: May 18, 1980; 57 people killed
Avalanche: ran 15 miles; volume 0.7 cubic miles
Blast: Devastated 230 square miles
Ash Cloud: reached 16 miles high
Pyroclastic flows: were hotter than 800 degress F
Mudflows: traveled 75 miles
Size of Crater: 1.5 by 1 miles; 2,000 feet deep
Smaller Explosions: May 25, June 12, July 22, August 7, and October 16, 1980
Lava Dome: grew in pulses from October 1980 to October 1986; in 1992 it was about 1,000 feet high
Estimated time for pre-1980 forest recovery: 200 years
Future eruptions?: Yes. When? Not known


From Castle Rock take Interstate 5 north to exit 68, then turn east on Highway 12 toward Randle. This 66-mile drive roughly follows the Cowlitz River which has been dammed to form Mayfield and Riffe Reservoirs.

If the day is clear you will be able to see Mount St. Helens, 24 miles away, from a viewpoint just north of the highway. Watch for a sign 4 miles past Mossyrock dam; drive to the end of the 1-mile road and look south. You'll see Mount St. Helens' unmistakable profile and, if you have sharp eyes, the dome inside the crater. Back on the main road, keep an eye out, too, for glimpses of Mount Rainier and Mount Adams -- they can be seen from several places along Highway 12.

Check your gas gauge at Randle; you will be heading into back country where there are no gas stations. Turn south on Road 25, and nine miles south of Randle take Road 26 to the right (set your trip meter to zero at this intersection, or note the mileage indicator). The first stop will be in 9.2 miles.

LOOK This narrow, scenic road climbs steadily into the high country north of Mount St. Helens. Your pace will be slow; the speed limit is only 25 mph, which is reasonable considering the road is one lane wide with two way traffic and turnouts for passing every few hundred yards. Stands of old-growth conifer forest here alternate with areas that have been logged. Hardwoods -- especially red alder and maple -- grow where clear cuts have not been replanted. The understory consists of plants like elderberry, ferns and vanilla leaf.

In early summer you will see white plumes of blooming goatsbeard and flower heads of tall cow parsnip. At (4) miles an old-growth conifer forest provides a glimpse of what this entire region looked like a hundred years ago.

At (8.0) miles a gravel road on the right leads to Quartz Creek Big Trees. If you are early enough to take a short side trip, drive this 1.3 mile road leading to a loop trail that winds through a lovely old-growth forest or western red cedar and Douglas-fir. As you walk among them try to imagine trees this size -- some as tall as 200 feet -- obliterated in moments by volcanic force. If you do take this side road, remember to add 2.6 miles to your mileage totals beyond this point.

Destruction's Edge

OUT (9.2) Pull into the small turnout on the right. You are at the very edge of the area that was devastated by the 1980 eruption. Mount St. Helens, the source of the blast, still 13 miles to the south, is out of sight beyond the ridges ahead. Many of the scorched and downed trees in this area were salvaged after the eruption, so it is difficult to see the blast effects clearly. Live old-growth trees can be seen high on the slopes above the road, showing that the blast cloud was channeled down this valley of Quartz Creek. The next stop will be in 3.5 miles.

LOOK Waterfalls along here may be rushing or trickling depending on snowmelt or rainfall. One of the prettiest is the waterfall on Quartz Creek at (10.4) miles. The Cascade Range generally has high winter snowfall and dry summers.

Ryan Lake

HIKE (12.7) Turn right into the parking area and hike the 0.6-mile loop trail. This easy trail climbs up for a view of Ryan Lake, and then over the ridge to look into the Green River Valley and the Mount Margaret back country. Signs along the path tell about the destruction and recovery of this area, as well as the salvage operations.

A camper on the north side of Ryan Lake was killed by the 1980 eruption. Like many victims in the devastated area, he was suffocated by the hot gases and ash in the blast cloud. The downed trees around the lake have been left in place even though this area is outside the national monument. Farther from the shore of the lake, downed trees and standing but scorched dead trees were salvaged for lumber in the early 1980s. After the salvage operation the area was replanted, and by 1992 the young Douglas-fir along the loop trail were 8 feet tall and growing about a foot a year.

Ryan Lake did not have the ice cover that higher lakes did when Mount St. Helens erupted. Vast quantities of organic debris were hurled into the lake, drastically altering its chemistry. The oxygen in the water was used up by microbial activity, killing all the fish. Five years later, though, water chemistry had almost returned to normal, and many forms of aquatic life were beginning to return. By now Ryan Lake is essentially back to normal.

The loose gray, sandy material along the trail is ash from the blast cloud. The ash layer is about 3 inches thick, and on top are pebbles of buff-colored pumice that showered down from the high eruption cloud following the blast. Pick some up to see how light these bubble-filled lumps of volcanic glass are, but don't carry them away; toss them back for the next hikers to look at.

Golden-mantled ground squirrels abound at Ryan Lake, begging brazenly in the parking lot. They will pose for a picture but if you reward them with picnic snacks, you...

may be killing them. Their buried stores of wild seeds last through the winter, but snack food stored with it can spoil a whole cache and cause starvation.

Turn right on Road 26; the next stop will be in 1.5 miles.

Blowdown Area

OUT (14.2) Pull into the small turnout on the right side of the road. The blown-down trees in this headwater area of the Green River have been left exactly as they fell. Notice how the alignment of the logs on the hillsides ahead shows the swirling patterns of motion within the blast cloud. Nearer to Mount St. Helens the trees were blown down pointing away from the crater, but at this distance gravity and topography began to deflect the heavier-than-air mixture of hot gas and rock fragments. Trees might have been able to withstand the hurricane-force winds, but the push of the dense, ash-laden cloud was too great; once the trees began to fall, they took others with them like tumbling dominoes.

Count the years since the great eruption -- recovery here is slow. In 1992 the desolation of blown-down trees still dominated this view, but in another decade or two, new trees will begin to hide the scars from the great "stone wind".

The next stop will be in 2.7 miles.

LOOK The Norway Pass Trailhead at (16.5) miles is the starting point for an exciting 5-mile hike into the devastated area overlooking Spirit Lake (see page 43.)

Meta Lake

B>OUT (16.9) Pull into the turnout on your right for a quick look at this small mountain lake surrounded by blown down forest. From the next stop, in 0.7 mile, a short walk takes you to the shore of Meta Lake. Just ahead, at (17.4) turn right on Road 99 toward Windy Ridge.

Miner's Car and Meta Lake

HIKE (17.6) On May 17 1980, three members of a family parked this car beside a logging road and hiked to a nearby miner's cabin. The next morning they were killed. the...

cabin destroyed, and their car hurled 60 feet to this point by the blast. This place is still 9 miles from Mount St. Helens.

Such power is nearly beyond comprehension. The explosion was not nuclear, not chemical like TNT, but analogous to the bursting of a gigantic steam boiler. The blast cloud, laden with rock particles, surged outward at 200 mph. Its temperature was highly variable but ranged up to 500 degrees F. Witnesses who were just beyond its deadly range described it as a black turbulent cloud about 500 to 1,000 thousand feet thick that raced along the ground, climbing ridges and disappearing into valleys, only to reappear climbing the next ridge closer to them.

Take a short walk to Meta Lake to see this area recovering. This nearly-level, 1/2-mile round trip trail is barrier free for wheelchair access.

Unlike Ryan Lake, Meta Lake was covered with ice and snow when the eruption occurred. Fish, along with some amphibians and insect larvae, were able to survive under its protective cover. This lake too collected much organic material that disturbed its chemistry, but the melting ice left a lens of fresh water where fish could survive. The water here, too, is back to normal and able to support a rich variety of life.

The healthy young trees you see around Meta Lake are Pacific silver fir. They were small enough in 1980 to be covered by the snowpack, and survived while the taller trees were killed. Since 1980 they have grown and flourished out of the shade of the taller forest.

Notice that the observation platform is flooded; this happened when beavers returned to Meta Lake and built dams, raising the lake level. You can see the dams across the small stream as you walk back to the parking lot.

Turn right on leaving the parking area and follow Road 99 toward Windy Ridge. The next stop will be in 4.2 miles.

LOOK On clear days Mount Adams, 12,276 feet high and 28 miles to the east, dominates the far view. Geologists have determined that Mount Adams has erupted eight times since the last major glacial age about 12,000 years ago, but have no specific date for the latest eruption.

At (19.0) miles is Cascade Peaks Overlook, just outside the monument, where meals and snacks are available. Along here the road is the boundary of the monument, and this provides an interesting contrast in...

landscapes. On the right, in the monument, the area is recovering naturally. On the left, downed trees were salvaged and new trees planted for future logging.

Between here and Windy Ridge, road cuts reveal loose ash and pumice layers -- generations of fallout from Mount St. Helens. The layer on top, as much as 3-feet thick, is from the 1980 eruption; deeper layers are from five periods of eruptive activity that occurred between 150 and 4,000 years ago.

The parking area on the right at (20.4) miles is the trailhead to Independence Pass, a hike described on page 43.

Harmony Viewpoint

OUT (21.8) Spirit Lake, 600 feet below this overlook, has had a restless history. Born about 3,500 years ago when eruption debris from Mount St. Helens dammed the Toutle Valley, the lake rose higher when thick pumice deposits were erupted some 400 years ago. These changes occurred while Native Americans lived in areas surrounding the mountain. Their legends telling of evil spirits who inhabited the lake are probably based on episodes of sudden drops in lake level that must have been accompanied by destructive mudflows.

The spirit of the lake has had periods of beauty and tranquility as well. Many residents of Washington and Oregon remember fondly the happy summer camp days spent at Spirit Lake. Harmony Falls Resort, reached by boat, was a haven on the lake shore for people weary of cities and the pace of the 20th century. Canoeing on the pre-1980 lake, surrounded by old growth forest, was a time-trip back to the Northwest of the 1800s.

That tranquility disappeared in seconds of unimaginable violence as the giant 1980 avalanche swept down from Mount St. Helens. Hundreds of feet thick, and moving at express train speeds, the landslide slammed into the lake. Waves as high as 850 feet scoured the shores and washed thousands of shattered logs back into the basin. The blast from the pent-up volcano roared across the surging lake at nearly the same instant.

When the violence had abated, the first witnesses in rescue helicopters could hardly believe their eyes: the lake was a mile longer and 200 feet higher than it had been the day before. Its shores were swept clean; the surrounding forest was gone and a mat of shattered logs covered the...
dead lake. Steam explosions rose from the southwest shoreline as pyroclastic flows continued to sweep down from the crater.

It is quiet now, but the violence of that morning is still evident. If you have time you can hike down to the shore from here on a steep 1-mile trail to see the lake recovering from its most recent case of bad spirits. This is a research area, so be sure to stay on the trail.

The next stop will be in 2.8 miles at Windy Ridge. Smith Creek Viewpoint on the left at (23.4) miles is a good stop on your way back.

Windy Ridge

OUT (24.6) This is the major viewpoint on today's trip. At 4,000 feet in elevation, you are looking up to Mount St. Helens (8,365 feet) and down to Spirit Lake (3,445 feet). Take a look at the Panorama from Windy Ridge (156K) on pages 32-33 and with sharp eyes, or better still with binoculars, scan the horizon from right to left. Mount Margaret, to the far right, was well within the blast zone; in fact nearly everything in view from here is within the area devastated by the 1980 eruption. Harry's Ridge is named for Harry Truman, keeper of the Spirit Lake Lodge, who was killed when the huge avalanche buried his resort. The scar where trees and soil were scoured down to bedrock by the avalanche and blast can still be seen on Harry's Ridge.

The hummocky landscape between Harry's Ridge and Johnston Ridge is avalanche debris. The avalanche that triggered the 1980 eruption had so much momentum that it swept 1,200 feet up Johnston Ridge. Some of it topped the ridge and poured into the next valley (behind Harry's Ridge from this view).

Elk Rock, one of the major viewpoints on the Spirit Lake Memorial Highway, is 11 miles east of here. Between the edge of Spirit Lake below Harry's Ridge and the north base of Mount St. Helens is the pumice plain, formed when pyroclastic flows swept down over the avalanche debris, reaching the lake and causing large secondary explosions.

The "bathtub ring" of logs stranded by the high shoreline of Spirit Lake shows just how close the lake came to overflowing in 1982. If overflow had occurred, rapid erosion of the loose pumice and avalanche debris could have led to huge floods and mudflows down the North Fork of the Toutle River, even larger than the mudflows...

that accompanied the eruption. The Army Corps of Engineers used large pumps on barges and ran pipelines across the pumice plain to lower the lake level until the permanent drainage tunnel was finished in 1985 (see page 21).

The closest lake to Mount St. Helens and in the direct path of the blast and avalanche, Spirit Lake suffered the most destruction. Besides being choked by avalanche debris, ash, and countless tons of organic material, the temperature of the water was raised to almost 100 degrees F when pyroclastic flows poured into the lake. No life could have survived.

Spirit Lake went through the same drastic chemical changes that the smaller lakes did, but on such a large scale that some people doubted that it could ever support life again. Within five years, though, recovery of the water chemistry was almost complete. Addition of huge amounts of fresh water by rain and melting snow, and the stirring action of wind and waves adding oxygen were two of the most important factors. Spirit Lake today supports a wide variety of life ranging from algae to frogs; fish could live here too if they could find a way to get here.

The mats of logs you see floating on the lake once covered its entire surface. Some sink every year, but most will float for many years. The mats move across the water, nudged by the wind, changing the look of the lake every day.

The stump of Mount St. Helens is five miles from here. The lava dome inside the great horseshoe-shaped crater is just out of sight behind the northeast crater rim, but the remaining summit on the south rim, at 8,365-foot elevation, is visible at the back of the crater. The pre-1980 summit was 9,677-feet high, but that 1,300-foot loss is only part of the story; the crater is another 2,000-feet deep below the remaining rim. Did the volcano blow its top? Not really. Most of the summit slid away in the avalanche, and the resulting crater was enlarged by the blast and high ash cloud eruption that followed. About 90% of the missing mountain is in the avalanche debris.

The hill at the north end of the Windy Ridge parking area offers a spectacular view of Spirit Lake and the surounding country to those who climb the 368 steep steps to the top. Leaving Windy Ridge, backtrack to the intersection at Meta Lake. The next stop will be in 1.2 miles.

Smith Creek Viewpoint

OUT (25.8) Pull into the parking area on the right. The headwaters of Smith Creek, the steep slopes and valley seen from this viewpoint, were inside the blast zone, and are within the national monument. Their recovery has been and will be natural.

A mudflow poured down Smith Creek, into Muddy River and on into Swift Reservoir during the 1980 eruption. Fortunately it was much smaller than the mudflow that raged down the Toutle River, and precautionary lowering of Swift Reservoir before the eruption prevented any flooding down the Lewis River on the south side of Mount St. Helens.

A climbing party was near the summit of Mount Adams, the peak you can see looming over the near ridge, on the morning of the giant eruption. They could clearly see the blast cloud as it surged far out to the north, but the vertical ash cloud that followed disappeared above a high overcast. About 20 minutes later, things began to fall on them from that ash cloud. The first fallout was small, soft B-B-sized pellets, and then conifer cones singed and still hot when they landed. Falling lumps of pumice as large as 3/4 inch in diameter soon followed. Finer ash continued to fall until mid-afternoon as the climbers hurried down the mountain. Mount Adams was on the south edge of the ash-fall area, but winds that day carried the high ash cloud directly over Yakima in central Washington and Ritzville in eastern Washington.

At Yakima fine ash began to fall in mid-morning and lasted all day. Automatic street lights came on and the day was described as "black as the darkest night" even though the ash fall totalled only 1/2 inch. In Ritzville ash like talcum powder accumulated to a thickness of 2 to 3 inches. Car engine filters became clogged, people wore dust masks, and banks asked customers to remove their masks before entering. Ash fell in Idaho and Montana, and at mid-day May 19, a dusting fell on Denver. Removing the...

thicker ash layers on roads and towns was a costly nuisance. It was called "gray snow that doesn't melt", but it caused no major damage. In the long term the soils of the Northwest owe part of their richness to the nutrients that slowly weather out of volcanic ashes scattered from Cascade volcanoes.

If the Mount St. Helens eruption produced this tremendous amount of ash, why did it not have much of an effect on climate? Mount Pinatubo in the Philippines erupted in 1991, and its dust and sulfuric acid cloud is still (in 1993) circling in the stratosphere, lowering world temperatures by 1-2 degrees F and creating dazzling, multihued sunsets. The answer is threefold: first, the Pinatubo eruption was 10 times larger than this one -- hard to imagine when you are Iooking at the destruction here. Second, Pinatubo produced ash clouds that reached even higher than those from Mount St. Helens, pumping millions of tons of ash and sulfur gases high into the stratosphere where it is not washed out by rains; and third, the more equatorial latitude of Mount Pinatubo caused its dust and gases to circulate above both hemispheres of the Earth.

The next stop will be in 8.6 miles.

LOOK When you reach the intersection of Roads 99 and 26 at (31.9) miles, stay on Road 99 straight ahead. At (32.5) miles you begin to reach the edge of the blast zone, and the road zigzags in and out of blown-down trees and standing dead trees in the scorch zone.

Boundary Viewpoint

OUT (34.4) This is the boundary of the blast zone as well as the boundary of the monument. Clearwater Creek in the deep valley below flows into Muddy River and the Swift Reservoir. This is your last chance for a photograph of Mount St. Helens framed by the trees that were killed at the edge of the blast cloud. The next stop will be in 2 miles.

Bear Meadow

OUT (36.4) Two photographers, Gary Rosenquist and Keith Ronholm, were among the campers at this spot when the great eruption occurred. Their photos have been of important scientific and popular value, for they clearly and dramatically show what happened in the first minute of the eruption. The people here were also very lucky. This site is 10 miles from Mount St. Helens, but the blast lobe that surged north traveled 14 miles, and the lobe to the east 11 miles. Bear Meadow is in the notch between the two.

Witnesses who were here, and many others who survived, mention the frequent lightning bolts associated with the turbulent ash-laden eruption clouds. These awesome electrical discharges add one more element of terror to explosive volcanic eruptions.

The next stop will be in 5.2 miles. Turn left on Road 25 at (41.1) miles.

Iron Creek Falls

HIKE (41.6) Turn off in the parking area to the right and hike the 1/4-mile long trail (round trip) to the falls. This lovely waterfall and clear pool beneath it is surrounded by old-growth forest. It is the perfect place to be reassured that the Earth abides, and that much of the monument will look like this again someday.

This is the end of today's tour. Road 25 north will take you to Randle, or to the south to Cougar.


The 1980 eruption largely affected the west, north, and east sides of the mountain. If you have an extra day to spend at Mount St. Helens, though, some unique volcanic features and the scenic beauty of the South Side make it well worth a visit. Take Exit 21 off Interstate 5 at Woodland and drive Route 503, then Route 90, for 30 miles up the Lewis River Valley to Cougar (see pages 2-3). For directions beyond Cougar see the Map of the South Side (104K) on page 37.

Trail of Two Forests

HIKE Follow Roads 90, 83 and 8303 for about 10 miles northeast of Cougar to this unusual trail. At first glance it looks like a scenic, well-designed boardwalk path through a lush green forest; it is, but the real story is more complicated than that. The trail -- and the trees -- are on top of an old forest that was overrun by lava flows from Mount St. Helens about 2,000 years ago.

Flows of fluid lava called pahoehoe -- unusual for an explosive volcano like Mount St. Helens -- poured down the volcano's south slope and engulfed trees that were much larger than the ones you see here today. Most were felled and a few left standing, but all were killed. The lava cooled and hardened; the trees burned away, leaving molds of them behind with the imprint of bark still showing.

One reason the trees of the earlier forest were larger is that they were probably growing in a much deeper soil made up of layers of volcanic ash. In contrast, the live forest has grown on the thin soil on top of the hard lava flow.

From this 1/4-mile loop trail you look down into some of the tree molds, often with new trees and ferns growing inside them. The adventurous can climb down a ladder into one vertical tree mold and then crawl through two large molds that formed horizontally -- not a trip for claustrophobics.

Ape Cave

HIKE This large cave, a lava tube, is located about a mile beyond the Trail of Two Forests on Road 8303 (not plowed in winter). Lava tubes form in fluid lavas that issue from a single vent in a flow that lasts for weeks or months. As the main channel of the flow cools it roofs itself over with solidified lava, and the molten core continues to flow in a tube a few feet beneath the surface. This conserves heat and the flow can extend downslope for many miles. When the vent stops producing lava the molten core of the tube drains on down hill, leaving an empty tunnel behind.

The lava flow whose underground river of red-hot molten rock became Ape Cave coursed down a stream valley on Mount St. Helens about 2,000 years ago. Below here it burned and buried the trees seen in the molds at the Trail of Two Forests. Finding this Hawaiian-type lava flow here shows that not all the volcanic history of Mount St. Helens has been violent and explosive.

Ape Cave was discovered in 1951 and fully explored in 1958, and is the longest lava tube known in North America. From the broken hole in the tube's roof that forms the main entrance, the lower cave extends 4,000 feet downslope and the upper cave 7,000 feet upslope. Exploring the lower cave with good flashlights or lantern (available to rent near the cave entrance...

during the summer season) is easy, but leave the scramble over broken rock piles in the upper cave to the experts.

When a lava tube is active, the molten lava river often fills only half or less of the tube's diameter. Walking through this cool dark cave, can you imagine how it looked and felt 2,000 years ago? Maybe it's better not to.

Lahar Viewpoint and Lava Canyon

HIKE These two interesting sites (not open in winter) near the end of Road 83 show the power of mudflows. Lahar Viewpoint is on the wide barren deposit where the flood of water, mud and stones swept down Pine Creek on May 18, 1980. Lahar is an Indonesian word meaning volcanic mudflow. Many active volcanoes in Indonesia are surrounded by densely populated farm villages, and lahars there have killed thousands of people as well as burying large areas under thick layers of mud and gravel much like this.

Lava Canyon, a mile beyond Lahar Viewpoint, is an old valley on the side of Mount St. Helens that was filled by a lava flow about 3,500 years ago. Stream erosion then cut deep channels and potholes into the lava, and these were subsequently buried beneath later explosion and mudflow deposits. Melting snow and ice on May 18, 1980, sent a mudflow through here that ripped away some of these older deposits and exposed the ancient channels and potholes. Whether mudflows erode or deposit depends on their speed. At high velocities they erode; on slowing down they begin to deposit their load of mud and stones.

The top half mile of the Lava Canyon trail has been paved for barrier-free access by wheelchairs. Below that the trail continues for another 3 miles, becoming a more and more difficult scramble.

Cedar Flats Nature Trail

HIKE Cedar Flats is 20 miles east of Cougar on Roads 90 and 25. This delighfful walk is a 1-mile loop through an ancient forest of towering red cedar and Douglas-fir, growing on a terrace above the Muddy River. Everything from the high canopy through the understory of hardwoods like alder and maple to the lush forest carpet of ferns and mosses is in soft shades of green; soothing to the eye after viewing scenes of volcanic destruction. Notice the "nurse logs" -- fallen trees, decaying on the forest floor, that are fertile ground for mosses, ferns and seedlings of new trees. Straight rows of larger trees probably grew on a nurse log that has long since disappeared.

Be sure to stay on the trail; this is a research site for the study of natural processes in an undisturbed ecosystem.



From quiet cathedrals of ancient forests to the snow-clad crater rim, there are hikes of many moods at Mount St. Helens. More than 40 trails are listed in and near the monument and others are being developed. Volcanic landscapes, waterfalls, mountain lakes, big trees, and high-country views are among the types of scenery accessible by trail. A selected few of the many possibilities are listed below. Check at the Visitor Centers for information about other trails.

Norway Pass

This 6-mile-long trail between Norway Pass Trailhead on Road 26 and Independence Pass Trailhead on Road 99 (see pages 27, 29) is one of the most spectacular and beautiful at Mount St. Helens. It can be hiked in either direction but is most impressive from Norway Pass Trailhead (elevation 3,400 feet). After climbing for 2 miles, you suddenly have a view of Spirit Lake, the crater and lava dome from Norway Pass (elevation 4,500 feet, see photo on page 10 (65K)). Continue south to Independence Pass if you have arranged for transportation, or return to Norway Pass Trailhead. This entire stretch of trail is within the 1980 blast zone. Destruction and recovery seen everywhere along the trail provide a real-life experience in Nature's tough and tender ways.

Harmony Trail

From the Harmony Viewpoint on Road 99 (see page 29). hike down to the shore of Spirit Lake on this fairly steep, 1 mile-long trail. This was the site of a popular lake shore resort before it was obliterated by the 1980 eruption (see photo on page 31 (78K)). The present lakeshore is 250 feet higher than it was in 1979. From the new shoreline you have a good view of the lava dome in the crater of Mount St. Helens.

Truman Trail

This 7-mile-long trail (one way) from Windy Ridge winds down to the pumice plain. Here pyroclastic flows covered the avalanche deposits that buried Harry Truman and his lodge on the shore of Spirit Lake. The pumice deposits were so hot that they sterilized a large region. There were no surviving plants or animals, and the recovery of life had to begin by colonization from outside areas. Biologists are extremely interested in learning how this area will recover in a natural way. Hikers are required to stay strictly on the trail; wanderers from the Truman Trail are subject to substantial fines and the dismay of scientists who are trying to understand how Nature works in such a rare and undisturbed area.

Blue Lake

This small lake and surrounding forest, at an elevation of 3,300 feet on the southwest flank of Mount St. Helens, were little affected by the great 1980 eruption (see South Side Map (104K) on page 37). Hike about a mile along the Blue Lake segment of the Toutle River Trail from the trailhead on Road 8123. This stretch of trail wanders through a magnificent forest of old-growth noble fir.

June Lake

A 1.4-mile-long trail (one way) climbs alongside June Creek from Road 23 (see South Side Map (104K) on page 37) up to June Lake. The waterfall on the north side and a sandy beach on the south side make this small mountain lake a fine picnic site.

Mount St. Helens' Summlt

The 9-mile-long trail (round trip) from Climbers' Bivouac (elevation 3,750 feet; (see South Side Map (104K) on page 37) to the summit (elevation 8,365 feet) is an arduous trek and should be attempted only by experienced climbers. The rewards, however, are worth the effort. The view into the awesome crater, the huge lava dome, with Spirit Lake and Mount Rainier in the distance, is a glimpse of the primal Earth. Crampons and ice axe are needed for climbing the snowfields near the summit, as well as protective clothing for sudden storms that may occur even in July. All climbers must register before starting out and during May to November advance permits are required. Call or write Mount St. Helens National Volcanic Monument, 42218 N.E. Yale Bridge Road, Amboy, WA 98601 (telephone (206) 247-5800) for climbing information and permit application.


There are many motels and restaurants in the towns surrounding Mount St. Helens, but only two places to eat and no overnight accommodations in the monument. Cold water Ridge Visitor Center offers meals and snacks on the west side, and Cascade Peaks Overlook near Windy Ridge has meals and snacks on the east side.

There are also many campgrounds surrounding Mount St. Helens; the following three are near the roads described in this book:

Seaquest State Park -- across the highway from the Mount St. Helens Visitor Center, 5 miles east of Castle Rock. Telephone (206) 274-8633 for information and reservations.

Iron Creek Campground -- a Forest Service facility 10 miles south of Randle on Road 25. Telephone (206) 497-7565 for information .

Cougar Camp -- a tent campground maintained by Pacific Power and Light Company on the shore of Yale Reservoir just east of the town of Cougar. Telephone (503) 464-5035 for information and reservations.




Boly, William, FIRE MOUNTAIN. Portland, OR: Cathco Publishing, 1980.

Carson, Rob, MOUNT ST. HELENS. Seattle, WA: Sasquatch Books, with The Morning News Tribune, Tacoma, 1990.

Lauber, Patricia, VOLCANO, THE ERUPTION AND HEALING OF MOUNT ST. HELENS. New York, NY: Bradbury Press, 1986. (For young people).

Shane, Scott, DISCOVERING MOUNT ST. HELENS. Seattle, WA: University of Washington Press, 1985.

Quiring, James, MOUNT ST. HELENS: THE CONTINUING STORY. Las Vegas, NV: KC Publications, 1991.

U.S. Department of Agriculture, Forest Service, MOUNT ST. HELENS (MAP). Washington, DC: U.S. Government Printing Office, 1990.


Decker, Robert and Barbara Decker, MOUNTAINS OF FIRE: THE NATURE OF VOLCANOES. New York, NY: Cambridge University Press, 1991.

Harris, Stephen, FIRE MOUNTAINS OF THE WEST. Missoula, MT: Mountain Press Publishing Co., 1988.

Tilling, Robert, Lyn Topinka and Donald A. Swanson, ERUPTIONS OF MOUNT ST. HELENS: PAST, PRESENT, AND FUTURE. Washington, D.C., U.S. Government Printing Office, 1990.

Flora and Fauna

Arno, Stephen, NORTHWEST TREES. Seattle, WA., The Mountaineers, 1990 (Fifth Edition).

Matthews, Daniel, CASCADE-OLYMPIC NATURAL HISTORY. Portland, OR: Raven Editions in conjunction with the Portland Audubon Society, 1990 (Second Edition).

Niehaus, Theodore F. and Charles L. Ripper, A FIELD GUIDE TO PACIFIC STATE WILDFLOWERS. Boston, MA: Houghton Mifflin Company, 1976.

Underhill, J.E., UPLAND FIELD AND FOREST WILDFLOWERS. Blaine, WA: Hancock House Publishers, 1986.

Whitney, Stephen R., FIELD GUIDE TO THE CASCADES & OLYMPICS. Seattle WA: The Mountaineers, 1983.



All photographs in this road guide were taken by the authors except the following: Cover, Lyn Topinka, U. S. Geological Survey ( USGS), 1985; p5 Lyn Topinka, USGS, 1988; p7 Robert Krimmel, USGS; p8 (top) Katia Krafft; p8 (bot) Dwight Hamilton, 1955; p10 (top) Katia Kram; p10 (bot) Jim Quiring, U. S. Department of Agriculture, Forest Service (USDA-FS); p11 (top) USGS; p11 (bot) Dan Miller, USGS; p14 (top) Lyn Topinka, USGS; p14 (bot) Tom Casadevall, USGS; p15 (top) Tom Casadevall, USGS; p15 (bot) Chuck Tonn, USDA-FS, 1989; p22 Robert Krimmel, USGS; p31 Oregon Historical Society, Negative #70888; p39 (bot) Lyn Topinka, USGS, 1984; p42 (bot) Lyn Topinka, USGS, 1984; p44 (top) Richard Hoblitt, USGS; p44 (bot) John Dvorak, USGS; p45 (top) Charly and Jo Larson, USDA-FS; p44 (bot) Rick Hazlett; p48 (bot) Lyn Topinka, USGS.

Return to the top of this page

Return to the Electronic Volcano
Web Page by Elaine Anderson for the Electronic Volcano