Caving in the Canadian Rockies

An unforgettable spelunking adventure through Alberta’s Rat’s Nest Cave, Canada’s fourth-largest cave system

  • Jun 10, 2024
  • 1,442 words
  • 6 minutes
Explorers with Canmore Cave Tours descend into Rat's Nest Cave during the Explorer Tour. (Photo: Madigan Cotterill/Can Geo)
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I’m holding my hands inches away from my face but can’t see anything. I wiggle my fingers (protected by two layers of gloves), thinking I might be able to distinguish their shapes in the darkness, but still nothing. It doesn’t matter if my eyes are open or closed because pitch black surrounds me without the artificial light of my headlamp. In the distance, I hear a symphony of water droplets falling into a pool below, creating a rhythmic song that evokes a sense of calm. “It’s almost like the cave is playing a concert just for us,” says our guide, Jaimie McMahon.

We are 256 metres below the Earth’s surface in Rat’s Nest Cave, Canada’s fourth-largest cave system. It’s cold, damp, dark and musty, but my inner explorer has been unleashed and I am fully embracing the thrill of caving.

Ancient cave formations deep inside Rat's Nest Cave. (Photo: Madigan Cotterill/Can Geo)
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Located just 10 minutes outside of Canmore, Alta., Rat’s Nest Cave exists beneath Grotto Mountain and is a popular destination for outdoor enthusiasts. “This is not a show cave,” says McMahon. “There is no manmade assistance like walkways, lights or stairs, and you will likely find yourself doing a lot of bum scooching.” 

I’m joined by two guides and seven other cavers in The Grotto. This is as far into the cave as Canmore Cave Tours can take us on its signature Explorer Tour. With headlamps turned off, we sit in silence. I have explored cave systems before, but never like this. 

Cave tours are a rare find in Canada, says Adam Walker, owner of Canmore Cave Tours, adding that only three companies in western Canada offer this kind of wild caving experience. Since 1992, Canmore Cave Tours has run guided expeditions through Rat’s Nest Cave, a Provincial Historic Site home to 7,000-year-old bones, ancient pictographs, a myriad of cave-specific formations and, of course, bushy-tailed woodrats (also known as packrats). During our two hours underground, we experience it all. 

A bushy-tailed woodrat (packrat) inside Rat's Nest Cave. (Photo: Canmore Cave Tours)
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Prehistoric animal bones found inside the bone room of Rat's Nest Cave. (Photo: Madigan Cotterill/Can Geo)
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Preparation before exploration

A rack of bright red coveralls lines one wall of the equipment room — this is where the adventure begins. On the opposite wall is a map of the Rat’s Nest Cave system. McMahon points to a closeup portion showcasing the “Tour Side” and describes the route we’re about to take. This tour takes in just 10 to 15 per cent of the cave system. “There’s quite a long collection of passageways back there. To see the whole cave would take multiple days.”

Cavers gear up to enter Rat's Nest Cave, ensuring harnesses are tightly fastened and helmets are on securely. (Photo: Madigan Cotterill/Can Geo)
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After being fitted with knee pads, a harness, a helmet, gloves, a cow’s tail (a harness attachment), and coveralls, we pack our equipment into bright yellow backpacks and head to the cave. We dress in layers to stay warm as the temperature within the cave is just 4.5 C. The cave tours operate year-round, regardless of rain, wind or snow, because the cold darkness inside the cave is a constant. 

The cave is accessed via a rugged one-kilometre trail that winds its way up Grotto Mountain, the perfect warm-up for what’s to come. We hike over creeks, through the forest, and even spot a herd of elk. Very soon, we will be walking in this exact location — but below the surface. Blocked off by a thick gate, the entrance boasts one sign stating that the area is a Provincial Historical Site. Another sign gives a start warning: KEEP OUT.

The entrance to Rat's Nest Cave. (Photo: Madigan Cotterill/Can Geo)
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Pictographs inside Rat's Nest Cave, enhanced by DStretch. (Photo: Canmore Cave Tours)
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Walking through history 

Rat’s Nest Cave was first “discovered” by hikers in 1972, but the evidence suggests humans have been in the area for thousands of years. McMahon points to a smudge of orange above the cave entrance and explains that it is one of several pictographs. Years of weathering have rendered the drawings virtually invisible to the naked eye, but a software called DStretch has allowed researchers to digitally enhance the pictographs. “The pictographs are estimated to be hundreds of years old,” says Walker. “But the exact date is unknown.”

Writer Madigan Cotterill smiles at the camera before crawling through a "tight squeeze." (Photo: Canmore Cave Tours)
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After a short climb up a slippery rock face, we enter the cave and immediately clip our harnesses to a cable. It’s almost instantly damp and musty. Less than a metre behind us is a big drop called the Bone Bed, a deep pit containing hundreds of bones. “There are 37 different mammal species that have been identified,” says Walker. “Some of the species that have been identified there don’t exist any longer.” The bones of large mammals like deer, elk, sheep and bison have been found, which Walker explains were likely carried in by humans. 

Lying on my stomach, I shuffle forward and peer into the hole. I shine my headlamp into the darkness, but the pit is so deep I can’t see the bottom. When explorers first ventured into the cave, this was where most of the excavation occurred, explains Walker. The skulls of animals like bighorn sheep and bears were found, almost certainly brought in by humans. “It wasn’t just bits and pieces,” says Walker. “Whole animals were put in there. And big animals that weren’t exactly going to wander in there themselves. There’s no way a bison is going to wander into the cave on its own. It had to have been brought in by people.”

Into the abyss 

For the next two hours, I feel like I am in an Indiana Jones film. We manoeuvre through large caverns, clip in and out of cables and move ever deeper into the cave. The first small passageway is a man-made hole called “The Box,” a narrow tunnel with a wooden ladder built into the rock with a sharp turn at the bottom. “It’s about the size of a manhole,” says McMahon. “Just be careful to watch your footing, and try not to cause any rocks to crumble on the person in front of you.”

Canmore Cave Tours guide Jaimie McMahon looks down into "The Box". (Photo: Simon Cotterill)
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Cavers descend into the cave. (Photo: Madigan Cotterill/Can Geo)
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I watch as other participants easily navigate the hole and am pleasantly surprised when I make it through before entering a large room decorated with soda straws (tiny stalactites). It takes about a century for a soda straw to grow one centimetre, so we are instructed to be very careful to avoid touching them.

“Who wants to try a real squeeze?” asks McMahon. She points to a small gap between the rocks and tells us that we must navigate through on our stomachs, wiggle like a seal through the approximately six-foot space, and then roll over into the next cavern. Immediately, I think, absolutely not. But before I could even think about it, I am crawling into the hole. This portion is optional — there’s another route around the hole — but our entire group takes on the challenge and easily makes it through. 

An animal skull in Rat's Nest Cave's bone room. (Photo: Madigan Cotterill/Can Geo)
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Crouching, sitting and sliding, we move slowly, frequently stopping to learn more about the different formations around us. Midway through, we stop in an area of the cave with large blotches of white decorating the walls. “Moonmilk” is a substance left behind by the bacteria that eat the limestone on the cave walls. 

Finally, we emerge into the Grand Gallery. We spend some time testing out the acoustics and admiring the incredible surroundings. I can’t help but imagine how great it would be to host a concert here, then find out that actually happened in 2018 during Canmore Cave Tours’ unEarthed concert series. Rat’s Nest Cave made the perfect location for a truly “underground music” experience. A human chain helped to bring equipment into the cave before a one-of-a-kind performance, which included portions conducted in complete darkness. 

Our final stop was The Grotto. Beyond this point, an explorer needs scuba equipment as the remainder of the passageway is hidden beneath crystal-clear water surrounded by calcite formations. We pause, capture dozens of group images, and discuss the experience overall. For Walker, sharing this experience is one of his favourite parts about caving. “It’s such a weird experience,” he says. “It’s fun to see the reaction folks get when they go in here.” Caving is a mix of excitement and managing fears, but the adventure is truly worth it. 

Soda straws hang from the ceiling of Rat's Nest Cave. (Photo: Madigan Cotterill)
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Mushrooms growing inside Rat's Nest Cave as a result of spores being brought in by rats. (Photo: Madigan Cotterill/Can Geo)
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