Learn more about Frank Slide: when it occurred, its impact, and if we're likely to see another rock avalanche from Turtle Mountain.

When did the Frank Slide take place?

The Frank Slide occurred at 4:10 in the morning on April 29, 1903.

What caused the Frank Slide?

The primary cause of the Frank Slide was the unstable geological structure of Turtle Mountain.

The mountain’s once horizontal layers of sedimentary rock had been folded during the mountain building process until almost vertical – the ultimate in mountain instability. A major thrust fault – the Turtle Mountain Thrust Fault – runs through the mountain. The thrust fault further divides and weakens the layers of rock within the mountain. The erosion by water and ice of sandstone and shale layers on the lower half of the mountain beneath the older layers of limestone on the upper half of the mountain created a significant overhang. Large surface cracks along the summit of the mountain allowed water to enter deep within Turtle Mountain. Water continued to eat away at the limestone and the freezing and thawing action of water and ice worked to widen the cracks, creating even more instability.

Turtle Mountain was a mountain ready to fall. It was just a matter of time.

Immediately following the slide, coal mining, which had begun in 1900, was blamed for the disaster. In the years following the slide, coal mining has been identified by scientists as a secondary or contributing factor, but it was the unstable geological structure that was the main cause of the massive rock avalanche. 

How long did it last? How loud was it? How fast were the rocks moving?

People for many kilometres around heard the roar of the slide. It was so loud it is said that some people in the town of Cochrane, outside Calgary – over 200 kilometres (120 miles) away – heard the noise from the Frank Slide. 

Ear-witnesses in and around Frank said the slide lasted approximately 100 seconds and the sound was like steam escaping under high pressure.

Based on how far the rocks extend across the Crowsnest River valley and the time the slide lasted, scientists estimate that rocks were moving at speeds up to 120 kilometres/hour (70 miles/hour).

How much rock fell? How much area did it cover in the valley?

Scientists have estimated that the block of rock, mostly limestone, which fell from the top of Turtle Mountain during the Frank Slide was approximately 1 kilometre wide, almost half a kilometre (425 metres) high and 150 metres thick. This calculates to a volume of approximately 44 million cubic metres of rock, or 110 million metric tonnes.

An area of 3 square kilometres on the valley bottom was buried to an average depth of 14 metres (46 feet), with some spots as deep as 45 metres (150 feet).

To put it all into perspective, it has been calculated that you can build a wall 1 metre wide and 6 metres high all the way from Victoria, British Columbia to Halifax, Nova Scotia using rock that fell from Turtle Mountain during the Frank Slide. Amazing!

How many people were killed? How many people survived?

Of the 600 people living in Frank at the time of the rockslide, over 100 were in the path of the rocks. Of those, more than 90 were killed. In fact, because the bodies of most victims were never recovered, there has never been an exact number of victims established.

Seventy people were reported dead in the Frank Sentinel paper at the time of the slide. Twenty-three very lucky people in cottages in the southeast edge of town survived the slide. Seventeen miners inside the mine survived but were trapped and had to rescue themselves.

Approximately 500 people in the townsite of Frank were not touched by the rockslide, but probably considered themselves to be survivors of the Frank Slide.

Were all of the bodies recovered from the slide?

No, this was impossible due to the depth of the rocks, up to 45 metres (150 feet) deep. However, there were 12 bodies pulled from the shallower rubble along the western edge of the slide in the first few days after the catastrophe. Approximately 80 bodies were unaccounted for.

In 1922, a road construction crew uncovered a home, believed to belong to the Alfred Clark family, and 6 more bodies were recovered.

What about the baby girl who was found on a rock? Who is “Frankie Slide”?

The story of “Frankie Slide,” a baby girl who was the only survivor of the Frank Slide is erroneous, though one of the most famous myths. This story does have its roots in bits of truth, as there were several young girls who survived the disaster.

Twenty-three people in the 7 cottages on Manitoba Avenue at the southeastern edge of the town survived the rockslide. This included 3 young girls.

The first was Fernie Watkins, a 3-year-old girl found in the debris outside her family’s home by the pit boss at the mine, Edgar Ash.

The second was Marion Leitch, 27 months old, who was thrown from her house when the rocks hit. Marion was supposedly found on a pile of hay beside the house.

Gladys Ennis was 15 months old at the time of the disaster and was found choking on mud thrown by the slide that destroyed her home. Lucy Ennis or Sam Ennis, Gladys's parents, saved her life, as one of them cleared their daughter's nose and throat of mud.

False stories spread around the world about a single baby girl, named “Frankie Slide” by her rescuers, who was the only survivor from the town of Frank following the slide. As noted, there were 3 young girls who survived the slide, plus 20 other people pulled alive from the rocks, along with the over 500 people from the townsite of Frank who were not touched by the slide at all.

Are there any survivors from the slide still living?

No. The last survivor to pass away was Gladys Ennis, who died in Bellevue, Washington on March 20, 1993 at the age of 91.

Why is the disaster called the Frank Slide?

When the rockslide happened in 1903, although it fell from Turtle Mountain, it covered a portion of the community of Frank, earning the name the Frank Slide. Frank was named in 1901, after its founder, Henry Luplin Frank, a businessman from Butte, Montana who saw opportunity in the great coal deposits of the Crowsnest Pass.

What was destroyed in the slide?

Destroyed were:

  • Seven miners' cottages—6 inhabited at the time—on Frank’s easternmost street, Manitoba Avenue
  • All of the surface buildings of the Canadian American Coal and Coke Company
  • The McVeigh and Poupore construction camp
  • A dairy farm, 2 ranches, a shoe store, a livery stable, the Frank cemetery, 2 kilometres of cart track
  • 2 kilometres of Canadian Pacific Railway line
  • 1.5 kilometres of the just-completed Frank and Grassy Mountain Railway line

If the entire town wasn't destroyed in the slide, why is it not at its original location?

In 1901, the original townsite was established at the base of Turtle Mountain. This provided easy and quick access for workers to the Canadian American Coal and Coke Company mine, which began producing coal in 1901.

After the Frank Slide fell in April of 1903, some people from the townsite of Frank began to move away, fearing another massive rockslide. Many people stayed and Frank grew from 600 inhabitants at the time of the slide to a population of 1,000 by 1910. As the townsite expanded, there was nowhere for it to grow eastward, so the community of “New Frank” took root just northwest of the original town across the Canadian Pacific Railway tracks.

In the years following the slide, scientists studied Turtle Mountain very closely to determine whether another slide would come down. In 1911, a Royal Commission of scientists found the north peak of Turtle Mountain to be structurally unstable and determined that the townsite of Frank was in danger. In reaction to the Royal Commission, the provincial government ordered that all buildings from “Old Frank” be moved.

Over the next few years, nearly all of the buildings of Old Frank were either dismantled or relocated. Some buildings were moved to other areas of the Crowsnest Pass with a few moving “across the tracks” to New Frank. The Imperial Hotel was moved all the way to Vulcan, Alberta.

Today, the community of Frank is part of the Municipality of Crowsnest Pass and is located on the north side of Highway 3 (Crowsnest Highway) at the location of what was once known as New Frank.

In recent years, scientists have determined that the North Peak of Turtle Mountain is unlikely to produce a rock avalanche of significant volume. The Frank Industrial Park—south of Highway 3 and the C.P.R. line and below the cliffs of Turtle Mountain—now occupies the original 1901 townsite of Frank.

Will more of Turtle Mountain fall in the future?

Scientists believe that another significant rock avalanche will occur at some time in the future on Turtle Mountain. Turtle Mountain continues to move—at a few millimetres per year—to the northeast toward the valley below. Over time, the forces holding up the top of the mountain will be overcome by gravity and another large mass will break loose and tumble into the valley.

Scientists now focus on the south and third peaks of Turtle Mountain where a series of large cracks suggests that this will be the location of the next large rockslide.

Upper South Peak, Lower South Peak, and Lower Third Peak are possible sources for rock avalanches involving significant volumes of rock. Scientists have been studying this part of the mountain for decades, and in recent years very sophisticated monitoring equipment has been installed on the mountain by the Alberta government.

Scientists from the Alberta Geological Survey keep a close watch on all of the real-time data that is transmitted from the monitoring equipment on Turtle Mountain. Scientists suggest that if all of the zones of instability on South and Third Peaks gave way at once, the resulting rockslide would be approximately 1/6 the size of the original Frank Slide and would fall along the eastern edge of the original slide. It’s likely that a rockslide of that size would cover approximately 12 homes in the valley below and would reach the rail line and maybe even the highway.

Turtle Mountain is currently monitored by several state-of-the-art technologies and the continuous data stream from this network provides valuable insights into the mechanics of the slowly moving rock mass. Scientists estimate that any major rockslide from Turtle Mountain is not likely to occur anytime soon if the mountain continues to move at its current slow, turtle-like pace. However, if movement begins to speed up, a major rockslide could happen much sooner. And, if an earthquake happens nearby, all bets are off.