Why cave exploration matters

2022 is the International Year of Caves and Karst. Here’s why you should care about the hidden worlds beneath our feet.

  • Published Jun 24, 2022
  • Updated Jul 11
  • 2,517 words
  • 11 minutes
First Canyon in Nahanni National Park Reserve, Northwest Territories. Cave entrances can be seen high in the cliffs. The incredible karst of the park reserve is one feature which led to its establishment as a UNESCO World Heritage Site, a designation which was spearheaded by leading speleologist Dr. Derek Ford. (Photo: Greg Horne)
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“The ultimate aim of all science is to penetrate the unknown. Do you realize we know less about the Earth we live on than about the stars and galaxies of outer space? The greatest mystery is right here, right under our feet.” 

The words of geologist Oliver Lindenbrook in the 1959 film Jules Verne’s Journey to the Center of the Earth highlight the human desire to seek unknown worlds and make new discoveries. While the story is science fiction, science fact is that unknown worlds do exist, and some of the most incredible undiscovered landscapes lie right beneath our feet.

These hidden worlds include caves and karst. Caves are found throughout Canada and around the world, but few people appreciate their value to humanity. Karst, created by the dissolution of bedrock, is even less understood. Karst landscapes comprise up to 20 per cent of the world’s surface, but are mostly hidden from view in the form of underground drainage networks. Karst aquifers provide an estimated 16 per cent of the world’s drinking water and include the largest springs on Earth. As a result, civilizations have tended to cluster around karst. Caves, often developing within karst, are home to some of the planet’s most diverse, important, and rare ecosystems. To highlight their importance, the International Year of Caves and Karst was established under the patronage of the United Nations Educational, Scientific and Cultural Organization (UNESCO) with a goal to “explore, understand, and protect” these fragile resources.

“In order to study and understand hidden features, the first step is to explore them,” says John Pollack, a former senior research scientist for the B.C. provincial government and past chair of the Royal Canadian Geographical Society’s Expeditions Committee. “Why does the Earth look the way it does? Geography and geomorphology are the first step in understanding our world, and karst is a phenomenal landform to study.”

We owe much of our current understanding of caves in Canada to Dr. Derek Ford and his research teams. “Ford realized that to study this geomorphology you had to go deep into the environment,” says Pollack. And he did, becoming one of the foremost speleologists – cave and karst scientists — in the world and sparking an unprecedented era of cave exploration and discovery in Canada that continues today.

Catherine Tardy-Laporte uses bridging techniques to traverse through “The Second Fissure” in Castleguard Cave. Castleguard Cave has kilometres of these deep “vadose” passages which must be crossed by cavers. (Photo: Christian Stenner)
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The beginning of an era

After emigrating to Canada in 1965 from his home in the Mendip Hills of the United Kingdom, Dr. Ford, his wife, and two graduate students drove west. At the time, Nakimu Cave in British Columbia was considered the longest in the country, with just over one kilometre of mapped passages.  Nakimu was well-known; during its heyday from 1906 to 1925 it was an exciting excursion for rail passengers making their way through the Rocky Mountains. The cave was closed to visitors in 1935, but the opening of the Trans-Canada highway through Glacier National Park spurred a renewed interest in discovering its secrets. Enter Ford and his team from McMaster University. Inside Nakimu, they explored never-before-seen underground rivers and waterfalls, increasing the known length of the cave to over four kilometres and establishing a depth of 270 metres.

The caving boom had begun. Within a few years, teams of researchers and rugged adventurers were combing the karst landscapes of Canada, searching for new caves and probing their depths to learn more about their origins and significance. One important site lies in Jasper National Park, home to what is thought to be Canada’s greatest undiscovered cave. The “Maligne Master System” is a substantial underground drainage system linking Medicine Lake with Maligne Canyon, some 15 kilometres away. Hydrological studies have proven an underground connection between the two, and Ford’s team spent five weeks in the area in 1967. They scoured every crack and canyon in the area and found over 80 tiny springs, but all were too small for humans to enter. Their dejection was shortlived: Towards the end of their expedition, Red Creighton, a Jasper local, dropped into their camp and said: “Have you heard of the cave in Castleguard Meadows?”


Its status as the longest cave in Canada, its remote, alpine setting underneath the Columbia Icefield, and its incredible features and fauna have made Castleguard a focus for explorers and researchers from around the world for over 50 years. 

“With Castleguard there was true international exploration in Canada. Looking around the campfire you could see renowned scientists, cave explorers, and graduate students from all over the world,” says Pollack, who was a part of some of the approximately 25 documented expeditions to the cave. Castleguard is the only known cave in the world where glacier ice intrudes into the limestone passages. In passages furthest from the entrance, the bottom of an ancient ice sheet completely blocks the way. There, cavers are directly beneath the Columbia Icefield, isolated by the days of underground travel required to get back to the entrance and cut off from the surface by an impenetrable 234 metres of rock and ice. To this day, this spot has only been accessed by a handful of people.


Castleguard was the site of what Pollack describes as one of the top feats in Canadian exploration history. On one of the first trips into the cave, explorers Mike Boon and Pete Thompson pushed deep into the unexplored passages, traversing an unprecedented 10 kilometres underground. Their route took them through “the fissures” – kilometres of vadose (tall, narrow, rift-shaped) passages. Traversing them requires awkward, bridging movements while unprotected by ropes. When Boon and Thompson turned around, they found that the route back to the surface had flooded with water, trapping them within the cave. They found a flat, sandy area, dug a small bed in the sand, and waited together in the cold, damp, dark tunnel, lights turned off to conserve fuel.

Ford recalls the episode: “That was in summer, before we knew more about the seasonal flooding. We sent a party of three rescuers down to help.” After hours of uncertainty, the floodwaters receded, and a small airspace emerged in the passage near the ceiling. Boon and Thompson were able to escape, crawling through the frigid water and back to daylight. Ever since, expeditions into Castleguard have been restricted to wintertime, when no flooding has been observed. 

Salmasellus Steganothrix, a troglobitic isopod crustacean from Castleguard Cave. This tiny eyeless crustacean can be found in Castleguard, Rat’s Nest Cave and Cadomin Cave in Alberta. (Photo: Christian Stenner)
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An ancient ecosystem underground

Castleguard is remarkable not only for its length, complexity, and history, but also its unique inhabitants, like Stygobromus canadensis. An aquatic crustacean, Stygobromus canadensis is a truly specialized troglobite – a cave organism which lacks eyes and pigment, revealing its evolutionary history in a dark and sunless environment. Stygobromus canadensis is found only in Castleguard Cave, and then only in a few puddles and streams of water two kilometres from the cave entrance. That life of this kind exists underneath an area that up until recently was fully glaciated is remarkable.

“The glaciers in the area receded between 5,000 to 10,000 years ago. It’s hard for a human to comprehend due to our lifespan, but the surface landscape as we know it is crazy new,” says Greg Horne, a resource management officer with Parks Canada and a cave specialist. “It’s barely established itself, whereas a cave can be a one-million-year-old landscape.” Cave ecosystems are subglacial refuges that have protected rare organisms like Stygobromus canadensis throughout multiple glaciations. Around the world, caves consistently harbour life that baffles the imagination.

Today, these ancient underground environments are helping researchers understand one of the most important problems in human history: climate change. As Ford explains, “Caves survive in the landscape and store information longer than anything else. Using cave deposits, we can reconstruct records of paleoclimate ranging from 100,000 to 2.5 million years ago.”

Cave deposits, also called speleothems, include stalactites, stalagmites and a wide range of beautiful and wondrous phenomena created by the accumulated deposition of underground minerals. “Inside, they are like the rings of a tree and contain a climate record considerably longer than surface sediments and actual tree rings,” says Horne. Fluid inclusions — water trapped within the mineral layers of the speleothems — can be correlated to historical precipitation levels. Studies in Canadian caves such as Castleguard, Rat’s Nest Cave, Grotte Valerie, and Ice Trap have revealed paleoclimate records dating back 700,000 years.

Cave deposits have also allowed us to gain insight into the reversal of Earth’s magnetic field. Iron oxide minerals become trapped in speleothems, and retain their magnetic polarity as aligned with the magnetic field of the planet at the time. “Speleothems have been found with metallic deposits that are magnetically reversed – meaning they reveal a time older than 780,000 years ago, before the last reversal,” says Ford.

Speleothems in Castleguard Cave. Mineral deposits form stalactites and other speleothems which contain a paleoclimate record dating back almost one million years. (Photo: Jeremy Bruns)
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Hidden caves, hidden feats

Conveying the significance of caves to a wider audience is challenging. Although discoveries in the Internet age have gained some public attention, it was not always so. In 1967, the Edmonton Journal dedicated 200 words to Boon and Thompson’s historic exploration of Castleguard Cave and did not name them.

There are a few reasons why caving has attracted less attention compared to other forms of exploration. The absolute darkness of caves makes it challenging to collect imagery that truly captures the nature of these underground worlds. Caves are also fragile and potentially hazardous environments, which has led cavers to keep locations and discoveries within a tight-knit community of explorers and scientists in an effort to keep the general public away. “Hidden caves equal hidden feats,” says Pollack. “Conditions underground are rugged and uncomfortable. They are cold, wet, dark, and contain vertical drops. They are specialized environments which require special skills and equipment.”

But secrecy can undermine efforts to help people understand and protect caves. “Canada is spoiled with water; we need to understand its importance and how groundwater moves through the Earth,” says Horne. “Caves are special resources and public education is needed so we don’t forget about caves and karst.”

The present and future of discovery

Fast forward to recent years, and the pace of cave exploration in Canada has continuously accelerated. A Castleguard Cave expedition in 2020 recorded a new length and depth: the cave is now over 21.3 kilometres long. Bisaro Anima, in British Columbia, became the deepest cave in Canada in 2018 and a 2021 expedition in the cave broke the depth record again. The cave is now known to be 683 metres deep, and over a kilometre of additional passages were discovered.

A massive cave entrance found in Wells Grey Provincial Park, British Columbia, in 2018 became a viral Internet sensation. Raspberry Rising cave, which cuts through a narrow band of marble in the Columbia Mountains of B.C., has been explored, revealing both a remarkably beautiful cave system and extremophile microbial life with properties which may be useful in the global fight against antibiotic resistance. Exploration of other cave systems in marble, called stripe karst, have potential to break more records. In 2022, a Royal Canadian Geographical Society-funded expedition will explore B.C.’s White Rabbit cave, a top contender in this category. 

Peter Chiba and Christian Stenner collect samples of speleothems deep in Bisaro Anima Cave. The samples are analyzed for the presence of extremophile bacteria (bacteria which can metabolize minerals instead of organic matter). Similar bacteria have shown antibiotic properties which may be useful in the fight against drug-resistant infections. (Photo: Stephen Gladieux)
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In 2017, intrepid cave divers reached a depth of 94 metres in a British Columbia cave called Hole in the Wall, the deepest cave dive ever recorded in Canada. Two centuries after it first became known to settlers, cavers from the Sociétê québécoise de spéléologie discovered an incredible extension to passages underneath the city of Montreal in Cavern St-Léonard. And on Vancouver Island, the place in Canada with the highest concentration of caves, an ongoing project seeks to dethrone Castleguard as the longest in Canada. As recently as 2019, cavers there found a connection between two neighbouring caves. The resulting combined cave system, ARGO, is now the second-longest in the country.

These examples showcase the ability of geography to drive a better understanding of our natural world. Understanding the world underneath our feet has broad implications, some of which we cannot foresee and will only be revealed with further study. Some of these projects will continue for many decades, a reflection of the complexity and difficulty of cave exploration, says Horne. “Mountains and other landforms can be seen, a finite resource in terms of physicality. Whereas in a cave, what you can see could be just scratching the surface.”

And what of the “Maligne Master System” which stymied explorers 55 years ago? “Canada’s greatest undiscovered cave is still Canada’s greatest undiscovered cave!” exclaims Ford. In a land where the peaks of the highest and most remote mountains have seen human footprints, and the surface of the earth can be remapped daily by satellite, the world beneath our feet remains one of the last unexplored frontiers of our planet. 

Stephen Gladieux, Peter Chiba and Christian Stenner at the entrance to Bisaro Anima Cave — Canada’s deepest cave — on the remote Bisaro Plateau, British Columbia. Smiles after reaching the surface after five days underground. (Photo: Carl Erickson)
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Sacred spaces

Canada’s national parks system owes its genesis to a cave. Millions of people have visited the Cave and Basin National Historic Site near Banff, Alberta, where hot springs on the flank of Sulphur Mountain have been a tourist attraction for over a century. The springs have been known to Indigenous Peoples for more than 10,000 years, since the last glacial retreat uncovered Alberta’s Bow Valley. The Blackfoot Nation referred to the area as Nato-oh-sis-koom, meaning “spiritual springs.” In 1883, after three Canadian Pacific Railway workers used a felled tree to descend through a skylight into a cavern there, a series of events led to the creation of the Banff Hot Springs Reserve, the predecessor to what is now the most visited national park in Canada.

There are many caves in Canada that were known and used by Indigenous Peoples long before settlers arrived. Though exploration beyond vertical drops requires modern safety equipment such as anchors and rope, the entrance zones of several caves show evidence of past human visitation. One such example is Rat’s Nest Cave, near Canmore, Alta. Inside is the bone bed, an amazing collection of the remains of 34 mammalian species spanning a 7,000-year timeframe. Two prehistoric tools were found while excavating the bones for study. One, a stone projectile tip made from “Banff chert,” dates to 3,200 years ago. Above the bone bed, the faint outline of a red ochre pictograph can be seen. And using DStretch rock art enhancement software, incredible handprints are visible in images of the rock outside the cave. The book Under Grotto Mountain by Chas Yonge describes these findings further, along with an affirmation from the Stoney Nakoda Elders: “Pictographs are ceremonial sites, places where the spirit world and the physical world are intertwined, and as such they should be respected and protected.”

Igniting the passion to preserve

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