The Night the Mountain Fell: The Story of the Montana-Yellowstone Earthquake

Dr. Merle Edgerton and his wife, Edna, in their car and trailer, were travelling with Harmon Woods and his wife, Edna, who also brought their car and trailer. Dr. Edgerton kept in daily contact with his hospital in Coalinga, California, up to the time of the slide. He was last heard from on August 15, giving the families’ location as “on the Madison River, outside Ennis, 35 miles from Yellowstone.”

The complete list of those who on such evidence are considered buried under the monumental Madison Canyon slide totalled 19. They are:

Sidney D. Ballard, wife, and son of Nelson, B. C.

Bernie L. Boynton and wife, Inez, of Billings, Montana.

Dr. Merle Edgerton and wife, Edna, of Coalinga, California.

Roger Provost, and wife, Elizabeth, and sons, Richard 16, and David, 1½, of Soledad, California.

Mrs. Thomas Mark Stowe of Sandy, Utah.

Robert J. Williams, and wife, Coy, and children, Steven, 11; Michael, 7, and Christy, 3 of Idaho Falls, Idaho.

Harmon Woods and wife, Edna, of Coalinga, Calif.

The other quake casualties include Mr. Purley Bennett and children, Tommy, Carole and Susan of Coeur d’Alene, Idaho, who, along with Thomas Stowe of Sandy, Utah, were found below the slide. Mr. and Mrs. E. H. Stryker of San Mateo, California, were killed by the boulders at the Cliff Lake Campground. Mrs. Myrtle Painter of Ogden, Utah, and Mrs. Margaret Holmes of Billings, Montana, died of quake injuries in the Bozeman Hospital.

The final Montana-Yellowstone Earthquake death toll stands at 28.

CD AND NATURAL DISASTERS

Natural disasters, like the Montana-Yellowstone Earthquake, are perhaps the best test of our Civil Defense readiness. Until the quake, CD Director Hugh Potter wasn’t at all sure that he had an outfit at all. Operating on a short budget of $21,000 a year, with all of the third biggest, sprawled-out state to organize, he’d set up, at least on paper, state-wide and county CD groups. He’d compiled an exhaustive inventory of state facilities, resources, etc., complete to such minutiae as the number of aspirins in the state (1,657,000 5-gr. tablets), and the amount of meat Montana’s abundant wildlife represented (58,517,725 lbs., including 1,000 bison, 415 grizzly bears).

The alerts he’d organized weren’t notable successes, and he’d caught some hell from the higher-ups for not being current on the state-wide alerts which are supposed to be held at least once a year.

“Our people just aren’t too enthusiastic about practice alerts,” Potter says. “Frankly, they feel it’s a waste of time. They’re busy. They don’t want to play war. A guy will say, ‘I want to go fishing, or put up a hay crop, or something.’

“But let a real emergency happen and they’re right there.

“During that first day Ed Cottingham and I were busy pulling triggers. I realized then that the most important thing I’d done during my seven years as CD director was getting around and getting to know who to phone—the people you can count on to get something done in an emergency. You can get the heck of a lot done if you know the right guy to call.

“There isn’t a CD department that didn’t check in right away to find out if they were needed.

“We’re especially lucky to have the U. S. Forest Service (the big slide happened in the Beaverhead National Forest) in our area. Their experience and constantly organized readiness to meet the threat of forest fires right now makes them an ideal outfit for any emergency. Forest Service firefighting squads, transport, equipment, and information about the area are all set up to move in a matter of minutes. They’re most adaptable to the kind of crisis the earthquake threw at us.

“You can tell the Forest Service your problem and quit worrying.

“Another important outfit is the Montana Forestry Department, which is set up to administer and protect the state’s forests. Its boss, Gareth Moon, is head of the CD’s Rural Firefighting Section.

“We have a good, mobile law enforcement outfit in the Montana Highway Patrol. The Montana Fish and Game Dept. men, in emergency, serve as an excellent backwoods force.

“Frank Wiley, Montana Dept. of Aeronautics director and one of the real pioneer pilots who can still fly anything from a jet to a Jenny, took over our flying problems.”

At 8:45 A. M., as part of a CD emergency plan called “Operation Bulldozer,” set up by the Associated General Contractors, Jack Marlowe, secretary of the Montana Contractors’ Assn., had completed a list and location of all heavy construction equipment in the area and reported that all contractors were on standby in case they were needed.

The State Dept. of Health was on the ball, too. They were moving in personnel to test water in Ennis, West Yellowstone and throughout the quake area by 9:00 the morning after the quake.

At 9:15 word came in that the Red Cross was flying in emergency personnel from the west coast.

Potter was thrilled by the offers of help that kept CD HQ phones busy. General Keith R. Barney of the Army Corps of Engineers called offering any help needed. The governors of Idaho and Wyoming and three Canadian provinces asked if there was anything they could do. Idaho’s highway patrol actually came up and helped keep things under control in the West Yellowstone area.

Several search and rescue outfits called, offering aid. A combined Army, Navy and Marine Corps Reserve unit from Butte gathered their medical equipment and ambulances and sped to the Ennis side of the slide as a voluntary, unpaid action.

There were offers from the crack mine rescue teams from the famous Anaconda Company mines in Butte. When a call went out on the regular radio for housing for the Ennis evacuees, several hundred accommodations were phoned in to a local Butte station. Another abortive suggestion that men on horseback might be needed to search some of the impassable back country brought over a hundred volunteers in less than an hour. A Bozeman station was overwhelmed with offers in response to an announcement that station wagons would be needed at the airport to ambulance the wounded to the hospital.

Nurses, doctors, National Guardsmen, skindivers—they all called in wanting to help.

At Great Falls, where the Montana Red Cross Blood Bank was holding a regularly scheduled drawing, when word came that they were flying blood to Bozeman to help the victims, so many volunteers showed up that the total exceeded 450 pints, and at closing time 150 donors were still in line.

“We had special problems—distance from any sizeable town was one. I’d hate to think of the casualties if the quake hit in a really populated area,” Potter said.

“The mountains, which obstruct short-wave signals and set up all sorts of radio blind spots, made it difficult to get any sort of ground radio communication going. It was impossible from the ground, to signal to Ennis or to Hebgen Dam from West Yellowstone. The radio amateurs did a tremendous job of helping those first few hours—they set up a standby network and kept it clear for emergency messages. One ham, Father Francis A. Peterson, (W7RKI), from St. Anthony, Idaho, one of the first to report the quake, loaded up his gear, drove to West Yellowstone, and by 7:45 A. M. the morning after the quake had set up radio control at the otherwise radioless West Yellowstone Airport. Another ham, Harold L. Beddor, (W7JPD), of Dillon, Montana, handled emergency communications from Dillon the day after the quake, then flew his equipment to the West Yellowstone Airport to help out too.

“The problem was complicated by the multiplicity of wave lengths on which the various civilian and military agencies were operating. We discovered that the high frequency bands the Civil Defense uses (150 megacycles) are useless in mountain country, especially in the day time. Lower frequencies, 34.82 and 46.86 megacycles did get through.

“All that first day or so, we relied on the Highway Department plane, which was radio-equipped, to get messages across the quake area. It stayed in the air all day.

“The mountain altitude (at the dam the elevation is 6,550 ft.), presented aviation difficulties, too. Smaller helicopters couldn’t make it, and some of the bigger jobs were tricky to fly in the less dense mountain air.

“We had difficulty with aerial sightseers. In spite of our announcement that the fields at West Yellowstone and Ennis were closed to all but emergency aircraft, planes flew in from all over. Charter pilots flew in from as far away as Arizona, and did a brisk business in flying the curious over the quake area at $6 a head. Including the Air Force ships, during the first few days the West Yellowstone Airport was as busy as Chicago’s Midway Field, with planes taking off and landing at the rate of one a minute. With all the traffic over the slide area, it was a miracle that we got through that first week without a crash.

“But as a result of the quake we know that any area which has this kind of emergency will make out OK with the wonderful spirit of people, helping and wanting to help.”

AFTERMATH

Among the cataclysms of nature, none is more terrifying than an earthquake, and huge slides, like the one triggered by the Madison Canyon earthquake, are perhaps the most dramatic type of geologic change. In one sudden, spectacular moment, changes take place that make us think of the tremendous energy released by atomic fission, the earth’s mass moves in a volume that rocks the imagination, and its effect on the people who are near, or in the path of nature’s huge, impulsive-seeming change helps us to realize how infinitesimal we are before the forces and laws of nature.

In 1903, a 40 million cubic yard rock slide crashed down from the crest of Turtle Mountain onto the coal-mining town of Frank, Alberta, killing 70 people.

But the consequences of such huge slides aren’t completed when the cliff toppling ceases. Take the case of the famous June 23, 1925, Gros Ventre slide in northwestern Wyoming, 40 miles south of Yellowstone Park. An estimated 50 million cubic yards of rock and debris plunged down the steep canyon wall, shot across the valley floor, and rushed some 350 feet up the opposite wall of the canyon before it settled back, like water sloshing in a huge bowl.

Nobody was killed when this slide choked the Gros Ventre River. It covered parts of two ranches and buried six head of cattle. But two years later, in May, 1927, the water dammed by the slide pushed out a big section of the slide and the sudden wave of water and debris washed away the town of Kelly, Wyoming, killing seven people.

This kind of possibility was in the mind of Army Corps of Engineers Missouri River Chief Keith R. Barney as he and Lt. Col. Walter W. Holgrefe of the Corps district offices at Garrison Dam in North Dakota, discussed the Montana earthquake’s action. The slide represented a double threat to people in the Madison Valley below.

As an immediate effect of the slide, the water flowing over Hebgen Dam was stopped by the slide. The formation of a lake behind the slide began the moment of the slide. When it filled, this 240-foot deep impoundment, called Earthquake or “Quake” Lake, would exert an enormous pressure on the slide. If the slide was composed of unstable material, its collapse could, in a repeat of the Gros Ventre tragedy, bring death and destruction to the valley towns of Ennis, Three Forks, and Trident below.

The second and greater threat was the discovery that when Quake Lake filled, its impounded water would lap at the foundations of Hebgen Dam, and quite possibly undermine it, releasing a volume of water seven times that of the earthquake-caused reservoirs, which could also sweep part of the slide along in its mad rush.

Like the threat of a time bomb, the rising level of Quake Lake, and the increasing pressure of the water against the slide, augmented by rumor, kept the downstream towns in constant anxiety.

The Army Corps of Engineers rushed into emergency action. They flew in a 50-man-staff, and set up headquarters in the Stagecoach Inn at West Yellowstone.

The mines in Butte were on strike, and huge earth moving equipment from the open pit operations, along with rigs from other contractors, worked around the clock to cut a 250-foot wide and 14-foot deep channel across the mile and a half long slide and armor it with rock so the water couldn’t cause sudden erosion of the rest of the slide before the water topped the huge natural dam.

On September 10, water licked over the new spillway, running into the river bed just below, which had been dry since the quake. To the Corps’s great surprise, severe erosion tore the downstream face of the slide. To remedy this, they launched another crash program to cut a 50-foot deep channel across the top of the slide. It was completed October 29.

The Corps’s operations on the slide took a total of close to $1,700,000 of funds set up for such emergencies. As a result, the towns below the slide are safe from the flood threat the slide might represent.

LIVING GEOLOGY

Just how common are mass earth shakeups like the Montana-Yellowstone Earthquake, anyhow?

Geologists tell us they’re frequent, with a dozen or more major quakes, and thousands of minor tremors happening each year.

Earthquakes are the natural outcome of the fact that the earth, while seeming substantial and changeless, is constantly, if most gradually, in the process of change. Mountains are thrust up. Glaciers carve them down. Volcanoes pour out their molten rock. Rivers and floods scour their erosive paths. Sediments slide and settle.

The enormous masses which great internal earth forces have raised up to mountain height, create counter stresses. These forces build up for years, sometimes for centuries or longer.

Eventually something has to give. When this happens on a grand, or spectacular scale, we call it an earthquake.

Whether you’re a connoisseur, expert, or not, the spectacular 1959 Montana-Yellowstone Earthquake was a beaut. Geologists call it a “textbook earthquake,” because it included nearly all of the classic actions, or results which quakes are likely to cause.

It ranked right along with San Francisco’s 1906 shakedown as among the severest earthquakes on the North American continent.

In seismic measurements, it rated 7.8 on the Richter Scale, as compared with San Francisco’s 8.2.

It set up so called tidal waves, or seiches, on Hebgen Lake. There were at least three of these huge waves—20-ft. high—which overtopped the entire 721-ft. length of the dam by four feet. Eyewitness statements relate that the velocity of the tidal wave was so great that it caused the water literally to leap over the top of the dam. It filled the small generating plant with a 2 to 4 ft. deep layer of rocks.

Although the dam stood, the quake caused several fractures in the core wall, one of which showed a 3- to 4-inch separation, and shattered the dam’s concrete spillway.

The earthquake created three major faults, with displacement on the Red Canyon Fault running as much as 20 ft., which stacks up impressively alongside the 26-ft. maximum displacement resulting from San Francisco’s quake. (These two earthquakes differed, however, in that the Montana displacement was vertical, while San Francisco’s was horizontal.)

According to the Society of Military Engineers, surveys from benchmarks outside the earthquake-affected areas show that the earth in the Hebgen Dam Quake area near Hebgen Dam has settled between eighteen and nineteen feet from its level before the quake.

It wasn’t uniform, though. The quake caused tilting, which showed up in the way the north side of Hebgen Lake had sunk eight feet, while the south side of the lake, docks, boats, etc., were sticking eight feet out of the water.

The quake also caused many sink, or more properly, blow holes. These phenomena are also known as sandspouts. Water, compressed and forced up and out by quake action washes out layers of sand sub strata. The overhead surface areas naturally drop into the hole, leaving a puzzling hunk of slumped ground—separate from the normal scarps—as big as 15 × 50 ft. in area.

The Montana-Yellowstone quake sent seismographs jiggling as far away as New Zealand. It caused fluctuation of water level in wells as much as ten feet in nearby Idaho, a tenth of a foot in Hawaii, 3,200 miles away, and .01 ft. in Puerto Rico.

The huge concrete Hungry Horse Dam, near Columbia Falls, Montana, 250 miles NW of the quake area, showed measurable displacement as a result of the quake. In remote Seattle, the diminished tremors were still strong enough to break loose the floating amphitheatre in Lake Washington.

But by far the most spectacular effect of Montana’s Earthquake was the huge landslide at the mouth of the Madison Canyon.

At the site of the slide, a relatively strong and nearly vertical layer of dolomite rock supported a huge bank, or mountain, of comparatively unstable schist and kept it from sliding into the valley in the same way that a retaining wall keeps a hillside terrace from slipping downhill. The tremendous shock waves of the earthquake fractured this dolomite buttress, and some 43 million cubic yards, or 80 million tons of rock, timber, and other mountainside debris cascaded off the slope, hurtled into the canyon, and surged up the opposite side, carrying huge trees and house-sized boulders as if they were weightless, hollow toys.

When this huge mass whomped down onto the river bed, it forced out the water and air trapped underneath at hurricane velocity. The huge slide spurted mud, air, and water with such force as to send two-ton cars sailing through the air, and to grind others to suitcase thickness against the rocks.

All this happened in seconds.

It would take eight seconds for the mass at the top of the mountain to fall to the valley floor 1,200 ft. below. At the time it reached this point, the mass would be travelling 174 miles per hour. The time it took to zoom half-a-mile across the valley, up the opposite canyon wall, then split and flow three-quarters-of-a-mile up and down the valley (the slide lies one-and-a-half-miles-long in the valley), was less than thirty seconds!

The fact that timber from the face of the mountain is spread in relatively uniform fashion over the entire surface of the slide is interpreted to mean that there was little tumbling action—that the slide moved as a single, if shattered, mass.

One important scientific controversy has emerged from the earthquake. It relates to the time relationship, or sequence between the initial shock, the tidal waves, or seiches, how fast the huge quantities of water which overtopped the dam moved down the valley, and whether these slugs of water had rushed through the canyon in time to reach the site of the slide before the mountain fell.

The stretch of the Madison running through the canyon is fresh, fast water, but normally it takes up to two hours for an object to run the sparkling, seven-mile, trout-rich stretch from Hebgen Dam to the mouth of the canyon. The big surges of water—the seiches overtopping the dam—would make it a lot faster.

There are two big, related questions.

Could the big surges of water reach the point of the slide soon enough?

And just how soon after the first shock did the mountain fall?

For the first couple of days after the quake, the theory persisted that the slide must have happened quite some time after the first shock—as late as 5:00 A. M., according to some theorists.

But, as the facts, and the testimony of folks trapped near the slide—the Osts, Fredericks, Smiths, and Mrs. Bennett—became available, it was apparent that the slide must have closely followed the initial shock. Even if you discount the disrupted time sense of people under stress—when a minute can seem like an hour, and vice versa—it’s difficult to imagine that more than 20 minutes elapsed between the first shock and the slide.

According to one set of calculations, big waves could have swept from the dam to the slide site in 18 minutes or so.

Hebgen Lake

Hebgen Fault

Red Canyon Fault

Although the quake caused much settling of the earth packed against the downstream side of Hebgen Dam’s concrete core, the relatively slight displacement of the sod cover is interpreted to mean that all three tidal waves passed over the dam before this earth subsided and separated from the core. Thus the water would have begun its race down the valley before the heavy earth-settling shocks hit the dam area.

Those who support the high-water-at-the-moment-of-the-slide theory point to the great volume of water damage way below the slide.

If the slide had come first, it would have dammed off the tidal waves, and prevented such damage. They feel there just wasn’t enough water in the river bed’s normal content to cause the water damage done both upstream and downstream by the slide. And they argue, the mud and dust in the composition of the slide would have taken up most of the water normally found in the reach of the river buried under the slide.

There’s further evidence in the numerous fish found high and dry on the flat along the river bank several feet higher than the streambed. Most of them were small, catfish-like chubs. There were numerous trout, and one 18-inch carp. There is no place in the river below the pool at the toe of the dam where carp would likely be found.

Also, there was further confirmation in the fact that three of the especially made 11-inch squared timbers, eight and a half feet long, with notched ends and two U-bolts used as stop-logs in the Hebgen Dam spillway were found below the slide. Some shadow was cast on this as absolute confirmation by the Montana Power Co.’s explanation that stop-logs have been lost from time to time before the quake.

Those who, in spite of such evidence, oppose the theory that the high water reached the slide area first just don’t feel that the water could have made it all the way down the canyon in so short a time. They feel that it would have taken at least 40 minutes for the big waves to traverse the seven miles. They have some support in L. D. Smith’s testimony that in driving down from Beaver Creek to Rock Creek right after the shocks, he saw no such waves.

At any rate, this is one argument that geologists and hydrologists will be batting around for a long time.

NOW YOU CAN SEE

It’s unusual when an event so spectacular as the Montana-Yellowstone Earthquake doesn’t produce some exploitable possibilities, and this one did. The month after this August 17, 1959 series of quakes, the U. S. Forest Service, which is proprietor of the vast and tumultuous real estate on which the major portion of the immediate quake action happened, announced that is was underway with plans to set up a Geological Area to help visitors get to earthquake interest points and to understand the tremendous earth forces which operated here.

They held the inaugural of the Madison River Canyon Earthquake Area—the first of its kind anywhere—on August 17, 1960, the first anniversary of the quake. Relatives of the 28 quake victims sat on the gigantic slide as they unveiled the bronze memorial plaque mounted on the huge dolomite boulder which had floated across the valley atop the surging debris.

This awesome and fascinating earthquake area quickly became one of the region’s top tourist attractions, with close to half-a-million visitors in attendance during each of the first two post-quake summers, in spite of miserable to nearly impassable access roads. This popularity is especially fitting because the quake that’s on display here was essentially a “tourist earthquake”. It happened in the scenic mountain area which draws a brisk vacation traffic from all over the U. S. and Canada, during the height of the tourist season. And those who went through the adventure, the thrills, the terror, the heroes and the helped, the survivors, and the casualties, could nearly all be classed as tourists.

Superb trout fishing has always been one of the area’s most important features, and, understandably, there was much post-quake concern as to how this would be affected. While Hebgen Lake was drained to repair the quake-damaged Hebgen Dam, Montana’s Fish and Game Department poisoned the trash fish and stocked the refilled lake with millions of rainbow trout running in size from fingerlings to 9-inchers. Today both Hebgen and Quake Lake—formed by the damming action of the slide at the mouth of Madison Canyon, afford top fishing, either from shore or from boat. Quake Lake has a made-to-order launching ramp at Cabin Creek, where the flooded-out road runs right into the lake.

In spite of the concern by fish biologists that silting from the slide would take the edge off fishing on the Madison below the slide area, it kept right on providing fishermen the top-notch action that had long earned its reputation as a blue-ribbon trout stream that compares with fishing anywhere in the world.

Today there are excellent roads to and through the Earthquake Area. Route 287, south from Ennis, leads directly to the huge slide at the mouth of Madison Canyon. Here the Forest Service has built a surfaced road up onto the slide. On top is the best vantage point to view the whole panorama of the mountain fall—where it dropped from, how in a matter of seconds 80-million tons of rock cut off the valley, the sparkling blue lake it created, and the open stretch of the Madison below the canyon. Besides, on the slide there are interpretive exhibits, and the huge monolith bearing the plaque to the quake dead, 21 of whom still lie somewhere beneath this mammoth pile of rock.

The relocated route runs eastward down the slide, along Quake Lake, and through Madison Canyon. Several Forest Service people staff the formally designated Earthquake Area during the summer season to help explain and interpret what happened here. Definite plans for the area include a formal visitor center, and at least one first-class campground in the slide-lake-canyon area.

Hebgen Dam, the dam that held, straddles the upper end of Madison Canyon. The road from here along Hebgen Lake to the Duck Creek Y has been much improved over its pre-quake status.

The Quake Area is just as easily approachable from West Yellowstone by taking 191 north 10 miles to the Duck Creek Y, and then driving west along Hebgen Lake. Near the Y, the big fault runs close to the road, through the Culligan ranch, etc.

The magnificent Raynolds Pass road, which runs south from its junction with the Madison Canyon road three miles west of the slide, has become an important new route to the earthquake area. The morning after the slide, highway crews were at work on this alternate route, which for two years substituted for the blocked, flooded, and destroyed road through the Madison Canyon and along the north shore of Hebgen Lake while the regular route between Ennis and West Yellowstone remained blocked. With its exciting mountain backdrop, this new, improved road provides an enjoyable alternative which should be included in any circle tour of quake features.

In the spring of 1959, as he tells it, Lemuel Garrison, Superintendent of Yellowstone National Park, looked at some bids for new housing in the Park which included extra steel as a protection against the possibility of earthquakes.

“Heck,” he said, “We’re not in an earthquake area.”

Today, Yellowstone’s famous earthquake has become an important addition to its already fabulous attractions. The Park took the quake in its stride. By June 1, 1960, in spite of road damage of $2,600,000, and building damage of $1,700,000 resulting from the quake, Yellowstone Park, its roads, and other facilities were ready for its normal summer rush.

In clearing a slide which blocked the road near Firehole Falls, south of Madison Junction, the road crew discovered one near casualty—a bear. The bruin had evidently sought shelter in a hollow below the road shoulder, and became trapped when the slide closed his exit. It was several days after the quake when the crew heard the bear’s attempts to crawl out of his artificial cave. They lowered a tree trunk, still bearing branches, into the hole and retreated while the bear scrambled out.

Word of the quake plus the initial belief that the epicenters of seven of the eleven major shocks were located in the famous Firehole Basin caused widespread anxiety as to whether the tremendous forces loosed might have interfered with nature’s intricate underground plumbing which keeps the geysers, hot pools, and mud pots spouting, burbling and burping.

Studies by a horde of seismologists, geologists and other earth scientists who swarmed into the Firehole Basin in the months after the quake show that during the night of August 17 the hot spring activity in this area changed more than during the 87 years since a park was created out of the mysterious, steaming country which had been known as “Coulter’s Hell.” The scientists termed these changes as “profound and far reaching.” These changes in thermal features are, and will be, in years to come, tremendously interesting.

The majority of these changes came with, or just after, the initial quakes. The earthquake acted as a trigger to start eruption in hundreds of springs, nearly half of them erupting for the first time in their known histories. The whole place blew, then subsided.

There was considerable juggling of the intervals and playing times of some of the better-known geysers. Great Fountain, Riverside, Daisy, Castle, and Oblong shortened the length of their eruption intervals, but they play nearly twice as frequently as they did prior to the quake. Sapphire, a minor geyser, became a major geyser, but has subsided to a status somewhere in between. Clepsydra Geyser went frantically wild, and has erupted continuously since the quake.

Steady Geyser just up and quit. So did Grand Geyser. Giantess Geyser, located just across the river from Old Faithful, habitually shook the ground in the vicinity every time it erupted. Right after the quake it blasted off and kept blowing for a continuous 100 hours, instead of its usual 30-hour run. The Fountain Paint Pots became so active, and spread so, that they took over what used to be an asphalt-paved parking area.

In the midst of these changing patterns, Old Faithful goes on in much the same way, except for perhaps a slight increased interval between blasts. Studies of 14,317 eruptions were clocked, with an average interval of 63.8 minutes. The shortest interval was 33 minutes, in 1948-51, the longest is 93 minutes, measured in ’55.

But none of these changes are static. Just when Grand Geyser, having been dormant for five months, was considered dead, it moved into a sporadic blasting phase.

These quake-caused fluctuations in thermal features, plus strong curiosity as to the earthquake’s effects in the surrounding area, Sup’t. Lon Garrison feels, will make Yellowstone’s post-quake years bigger than ever.

QUAKE LAKE

Smokejumpers

SLIDE

destroyed road

5 bodies found

19 presumed buried under slide

helicopter took victims here

Quake Exhibits

Old Madison Valley Fault

RAYNOLDS PASS

Raynolds Pass Road (replacing Madison Canyon road knocked out by Quake)

CLIFF LAKE

2 fatalities

RED CANYON FAULT

HEBGEN LAKE

HEBGEN FAULT

Road fell into Lake

Improvised road

Sandspout

4 Air Force Helicopters

WEST YELLOWSTONE

Injured transferred from helicopter for flight to hospital

MONTANA-YELLOWSTONE EARTHQUAKE

ABOUT THE AUTHOR

Ed Christopherson was a professional author and magazine writer whose articles about Montana, the Northwest, and other subjects appear in The Saturday Evening Post, Holiday, This Week Magazine, Mademoiselle, Reader’s Digest, The New York Times, Congressional Record, etc.

Born in Ohio, he began his writing career in New York. His introduction to the Mountain Northwest came through a season as a Forest Service Smokejumper. After several years in New York, he picked exciting and scenic Western Montana as the center of his regional writing activities.

Christopherson went to West Yellowstone (they called it “Shookville”) the day after the quake. He got first hand accounts from survivors there, and in Ennis, flew and walked over the slide and elsewhere in the quake area, and since has spent months researching and correlating what turned out to be “The Night The Mountain Fell.”

Transcriber’s Notes

• Retained publication information from the printed edition: this eBook is public-domain in the country of publication.
• Silently corrected a few typos.
• Transcribed some text within images.
• In the text versions only, text in italics is delimited by _underscores_.