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How a Team of Volunteers Discovered Canada's Deepest Cave

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Mexico isn’t the only country starting off 2018 with a new record in caving. Earlier this year Canada’s deepest cave was discovered in a remote mountain plateau in southeastern British Columbia. At just over 2,198 feet in depth, the Bisaro Anima cave is officially the deepest cave in continental North America outside of Mexico.

That depth was reached by a group of volunteers on an expedition that blended survey work and citizen science. It was led by Kathleen Graham, an amateur spelunker and president of the Alberta Speleological Society who, when not underground, is an accountant in Calgary, Alberta. Graham made the discovery on January 1, after descending nearly half a mile underground and encountering a sump, the caving term for a flooded passage. Donning scuba gear and plunging solo into the crystal clear water, she soon realized she was in Canada’s deepest cave.

“I was relieved,” said Graham, recalling that moment. “I was just like, okay I did it.”


The Bisaro Anima cave was discovered, and named, in 2012 by Calgary’s Jeremy Bruns, a mechanical engineer with a passion for caving. Since then, it’s been explored by Bruns and over 30 cavers through the multi-year Bisaro Plateau Caves Project, a volunteer-based endeavour whose latest record-breaking expedition was funded by the Alberta Speleological Society and the Royal Canadian Geographical Society.


The intense pressure and large quantity of melting water created by the retreating ice age-glaciers that once covered this part of North America are largely responsible for the region’s caves. But Bisaro Anima revealed itself to be special shortly after its discovery. “By the time we hit the second pitch (a vertical drop), which is 344-feet deep, or 35 stories, we figured that we’d hit something pretty big,” said Bruns.

After a 2016 expedition ran out of ropes and bolts, the Bisaro Plateau Caves Project regrouped this past October with the goal of finally seeing just how deep it went. Then the sump was discovered.


“We were totally not expecting that,” said Graham, who has been exploring the cave since 2012. “And I was not happy to see it.” Without any water exploration gear, their goal was temporarily put on hold.

The team was finally able to return from December 31 to January 6. The trip required three underground camps, the third of which became the deepest subterranean camp north of Mexico. Safety was paramount, particularity since the site was helicopter-access only. Thankfully the only serious injury the New Year’s team faced was one broken finger.


Graham and her team of volunteer cavers had used handheld laser distance measurers to conduct an amateur survey of the 3.29 mile-long cave’s drier portions. Measuring underwater after they arrived at the sump required a more old-school approach: A manual compass and a measured line. “There are more high tech ways of doing it, but that’s what I did,” Graham said.

Once in the near-freezing water, she started surveying. Though the expedition had packed two oxygen tanks, an accident emptied the air out of one. Conscious of her limited oxygen, Graham started her measurements on the surface while hoping to find a nice, big open passage.


“But nope, that wasn’t happening,” said Graham. “So then I dived down and I could see a tube that kept going. “ She was tempted to start exploring it, but her limited supply of air stopped her. “I told myself, it isn’t going anywhere,”she said.


While Graham’s underwater exploration only took her 49 feet below the surface of the sump, it was enough to cinch Bisaro Anima’s title as Canada’s deepest cave, pushing the previous record holder, the 2,149 feet deep Heavy Breather System, to second place. And the discovery of the tube means that Bisaro Anima might go even deeper.

While underground, the team collected water and soil samples, which are being tested by Kamloops B.C.’s Thompson Rivers University to see if they contain any ice age microbes. The team is also hopeful exploration of Bisaro Anima could be beneficial to scientists studying climate change. Graham explained that by studying the formations and contents of caves like this, we can gather tangible evidence of past climatic changes and how those changes have literally shaped our world.


The Bisaro Plateau Caves Project has several trips lined up for 2018, including a return to the sump, likely in the fall, when the frozen ground makes for a drier caving experience. Graham has big plans for that expedition.

“We want to go down that tube,” she said, noting that swimming through a dark, never-explored tunnel thousands of feet below the surface of the Earth will be the most technical dive of her 12-year caving career.


Bruns is excited about the attention that Bisaro Anima is bringing to Canada’s small caving community, noting that the country is packed with yet-to-be-explored caves.

“We really hope that this discovery encourages more people to get into caving,” he said.


Lindsay is a Toronto-based freelance writer who covers health, science and parenting.