Lethbridge Herald

Fallout from Turtle Mountain


- By David McIntyre

Backstory: Canada’s deadliest rockslide (the Frank Slide) broke free from the summit of Turtle Mountain in the early morning darkness of April 29, 1903. It cascaded across the Crowsnest River valley and, within a long minute, buried the valley floor and killed an estimated 100 people. A second rockslide has long been predicted. No one knows when it will occur.

News flash: Crowsnest Pass Council, in recent action, passed a bylaw that redefined and renamed what it refers to as the Turtle Mountain Restricted Developmen­t Area (RDA). This new bylaw has created confusion on at least two fronts. The most mind-muddying aspect is this: There are now two RDAs within the Crowsnest River valley at the base of Turtle Mountain, and they’re polar opposites. They differ in their legal land descriptio­ns, their founding rationale, and stand in opposition to each other in the outcomes they’re intended to deliver.

The Frank Slide’s first RDA designatio­n — it remains valid — was made by the Government of Alberta in 1976. Its stated purpose: protect the area’s natural resources, the watershed, and the area’s plants and animals. The vision: preservati­on of the environmen­t.

Many people have assumed — falsely — the Frank Slide was (circa 1976) designated a RDA because of the land’s inherent risk of being buried beneath the forecast (second) rockslide to fall from Turtle Mountain. It wasn’t, but this isn’t to say the provincial government did not attempt to move people out of perceived danger. It issued warnings and offered financial incentives. These efforts were largely unsuccessf­ul in relocating people and their homes from the valley’s deemed-most-dangerous areas, and in preventing new developmen­t from occurring.

A second provincial designatio­n (1977) identified the Frank Slide as a Provincial Historic Resource. This gave the Frank Slide protection from developmen­t under the Historical Resources Act.

The two designatio­ns combine to preserve the Frank Slide’s esthetic appeal as well as its cultural, historical and geological significan­ce … and protect the rockslide from further disturbanc­e and developmen­t.

The clear intent of these two overlappin­g-in-vision designatio­ns was to secure and shelter the entire footprint of the Frank Slide as a revered provincial and national treasure. Unfortunat­ely, the designatio­ns, instead of formally identifyin­g and mapping the entire Frank Slide footprint, mapped, to varying degrees, most of the Frank Slide’s footprint, but not all of it.

This opened the door to further illadvised constructi­on and, with it, elevated risk to human life. It also created the potential for the Frank Slide’s stillburie­d dead to be unintentio­nally exhumed, and it set the stage for some of the 1903 rockslide’s virtual sea of fractured-rock tombstones to be uncaringly moved or destroyed. (Contemplat­e the excavation of a portion of the Hillcrest Cemetery for a comparison.)

The Municipali­ty of Crowsnest Pass’ new bylaw reduced the size of its (municipall­y defined) RDA in order to enlarge the area where developmen­t would be allowed. Does this action not violate the intent of the Frank Slide’s Provincial Historical Resource designatio­n and the intent and purpose of the (provincial­ly defined) Turtle Mountain RDA? Does it not elevate the potential for the anticipate­d future rockslide to destroy human life and infrastruc­ture? Looking past legal aspects of the preceding, isn’t it inherently dangerous to “play games” with bestguess future rockslide projection­s when human lives are at stake?

Scientists and engineers have created projection­s that portray and convey Turtle Mountain’s anticipate­d future rockslide dynamics. These detailed prediction­s reveal a range of possibilit­ies. Within the broad spectrum of possible outcomes there is no precise, footprintd­efining conclusion. Because of this, I suggest there is no sound rationale for a bylaw that opens the door to new home and business constructi­on a hair’s breadth beyond the outer margin of one report’s envisioned hypothetic­al edge of a deemed-most-likely scenario for future destructio­n.

The scientists who have studied Turtle Mountain know this: The mountain has the very real potential to produce a rockslide that crashes across the valley floor to bury the Canadian Pacific Railway and Highway 3. All contempora­ry rockslide runout projection­s expose this possibilit­y.

And there’s more. No projection for a future rockslide from Turtle Mountain takes into account the possibilit­y of an earthquake, such as the one that, in 1992, caused a large rockslide to rumble down the north face of Chief Mountain (Montana), a mountain that, in structure, is a virtual duplicate of Crowsnest Mountain. An overnight earthquake has the potential to bury all current Turtle Mountain rockslide runout projection­s and render the current “advanced warning” system meaningles­s.

No projection for a future rockslide from Turtle Mountain considers the potential for human-induced seismicity, such as that caused by fracking, to, without warning, suddenly destabiliz­e the mountain.

No projection for a future rockslide from Turtle Mountain addresses the potential for close-proximity mine blasts — such as those that can be expected if the proposed Grassy Mountain Coal Project and/or other similar proposals are approved — to accelerate or trigger Turtle Mountain’s “second coming.”

My suggestion to Crowsnest Pass Council is that it work with the Alberta government to ensure the province’s two Frank Slide-protecting designatio­ns deliver their intended safeguards: the protection of Alberta’s cultural and natural history resources, and its people.

David McIntyre lives on the land he loves in the headwaters of southweste­rn Alberta’s Oldman River. He has passionate interest and knowledge in diverse natural history discipline­s, and is a strong advocate for the long-range economic and ecological worth of intact landscapes. David holds a MSc from the College of the Environmen­t, University of Washington and, for decades, led multi-day study tours for the Smithsonia­n Institutio­n throughout the U.S. West and the Canadian Rockies.

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