Beneath the Rockies: Exploring Canada’s Deepest Cave

18th February 2026 | Words by Aila Taylor

It is an afternoon in late autumn, the sun simmering low in the sky, as a helicopter whirrs over the Rocky Mountains. I peer out of the window, stunned by the view. In the valleys, larch and aspen glow gold with dying leaves, while above them the limestone peaks are extensively scarred by cracks and fissures. There is no sign of human civilisation here: only trees, rock and wind. But I see far more than this. Each crack is an unfinished sentence, and between the weathered rocks I see a treasure trove of possibilities.

This is the Bisaro plateau – the skin lying on top of the Bisaro Anima cave system. Already, this has been recognised as Canada’s deepest cave, though the full extent of the system has yet to be discovered. The cave is named after Private Torindo John Bisaro, a member of the Royal Highland Regiment of Canada who lived in nearby Fernie and was killed in action during the Second World War. ‘Anima’ is the Italian word for ‘soul’ – a nod to Bisaro’s Italian heritage. As well as a representation of Bisaro’s soul, the extensive depth of the cave has proven it to be the heart of the entire mountain range.

Bisaro Anima (colloquially, ‘Bisaro’) was first discovered and entered in 2012. Regular expeditions have been run to continue exploring and mapping out the cave system since then. In 2018, the expedition was named as the Royal Canadian Geographical Society’s ‘Expedition of the Year’, featuring in the award-winning documentary film Subterranean, which was released in 2023.

Down the Black Watch

Twenty-four hours after being dropped by helicopter on the side of the mountain – cut off from all contact with the rest of the world – I find myself descending into Bisaro for the first time. I am accompanied by my teammates, Matt and Lewis. We’re a Brit, a Canadian and an Australian respectively – testimony to the collaborative nature of this internationally renowned expedition. We are soon rappelling down the Black Watch, an enormous pit of 105 metres that descends into the dark depths of the cave. Drop a thought into it and it does not return. I trust the rope with my life as I abseil into it, the shadows rising up around me until I am the only person left in the world. Time seems to pause during my descent, until my feet land on the floor of rubble at the bottom of the pit. Lewis and Matt join me there, and we press on into a series of twisting tunnels, dragging heavy bags behind us.

Our mission for the day is to descend into the cave through the trade route and then ascend a series of avens (vertical shafts rising back up towards the surface) explored on previous expeditions. At the highest point – closest to the surface – we have been tasked with trialling new radiolocation technology to communicate with the surface team.

After climbing and crawling our way through a complex network of tunnels, we reach Camp 0.5 – the first of the underground camp locations in the cave – and tuck into some snacks that have been cached there from previous expeditions. The urge to unfold one of the stashed sleeping bags and curl up in the darkness is strong. Instead, we have a task to complete, and before long I find myself ascending the first of the ropes back up into the higher passages of the cave.

We find our rhythm, muscles burning as we climb higher, until we reach a point where we can go no further.

‘This must be the end point,’ I call down to my companions, ‘there’s no way up!’

‘Yep, I agree,’ Matt nods, ‘we’ve gone as far as we can go. Time to get the radio out.’

Matt and Lewis start playing with rods and wires, piecing together the new radiolocation system that will allow us to communicate with the outside world, even with hundreds of metres of rock between us. We have two other pieces of equipment which are less likely to work if the distance between us and the surface is too great: an avalanche beacon and a walkie-talkie. I climb up the aven as high as I can, carefully dodging the holds of loose rock that fall away in my hands, and balance the beacon on a narrow shelf.

Meanwhile, Lewis switches the walkie-talkie on.

‘I doubt this will work,’ he mutters. ‘But it’s worth a shot. Hello?’ he calls inquisitively into the walkie-talkie.

The three of us stand in silence, holding our breath. We know there is only a very slim chance of it working – but, as humans often do, we choose to hope.

‘Hello!’ A muffled reply shocks us through the speaker. ‘Are you out of the cave?’ The recipient asks. It seems that the surface team, too, have deemed the possibility of the walkie-talkies working improbable, and think the only explanation is for us to have exited the cave.

‘No!’ Lewis responds, laughing, ‘We’re still underground! We’ve reached the top of the aven.’

The connection can only mean one thing – that we are much closer to the surface than we thought we were. The three of us whoop for joy.

Unexpectedly, a crashing sound reverberates from above. For a moment, it sounds like a cave collapse, until the sound eases.

‘Helloooo!’ A voice with a Slovakian accent calls down.

I squeal with excitement. ‘Vlad!!’ I call back. ‘It’s Vlad!’ I shout excitedly to the others.

At best, we hoped to make contact with the surface today, and ascertain how far we would have to dig through to make a new entrance. At no point did we even consider the possibility of getting a voice connection almost immediately.

‘I’ll start digging!’ Vlad shouts with glee. In my 7 years of caving, I have never met anyone as enthusiastic about digging as Vlad. He is in his element when surrounded by unstable rocks, tunneling a new route into the earth, and with this – a dig that was guaranteed to break through – we had hit the jackpot.

As the passionate banging of rocks echoes down from above, Matt, Lewis and I pack up our equipment and tidy the radios away. It is about 2°C in the cave, and I soon start feeling cold with the lack of movement. We huddle together beneath an emergency blanket like hatchlings tucked beneath a mother’s wing.

Ten Metres of Rock

‘We should probably start heading out soon,’ Lewis comments a while later. ‘We still have a long way to go.’ He’s right. Although we’re around 10 metres away from the surface, our way out is blocked by an unstable clump of heavy boulders wedged in the rift. We will need to abseil down hundreds of metres, weave our way through the complex network of passages below, and ascend several large pitches – including the Black Watch – before we can leave the cave.

‘I know the plan was to leave the usual way… but the surface team are so close now. What if they break through, and we can leave through the new entrance?’ I suggest.

‘It’s certainly a possibility,’ Matt muses, ‘How about we stay here for another hour, and if they haven’t broken through by then, we’ll leave and stick to Plan A?’

We all agree that it sounds like a good compromise. As if on cue, a rock thunders down the aven, sounding much closer than the previous ones.

‘I’m going to send rocks down!’ Vlad shouts from somewhere above. ‘Hide somewhere safe!’

Emerging from our emergency blanket cocoon, we look around frantically. There doesn’t seem to be anywhere completely ‘safe’, but Matt spots a small alcove in the wall that should be out of the main firing range.

We tuck into it, pressing our knees to our chests, and once again cover ourselves with the emergency blanket. Now all we have to do is wait. The surface team get to work, while we occupy ourselves by playing dance music and having an impromptu rave beneath the emergency blanket. The onslaught from above becomes harder to ignore when a rock bounces off my head, jolting my neck with the impact.

‘I’m glad I’m wearing a helmet!’ I chuckle, trying to laugh it off. There is inherent risk in expedition caving. In addition to hazards such as loose rocks and flash floods, the remoteness of expedition caves makes rescue an extremely complex operation that isn’t guaranteed. When we choose to explore new caves, we accept this risk. It is a small price to pay for the gift of exploring places that no one has seen before.

After some more time listening to the barrage of boulders, our time is up. A wall of rock still stands between us and the surface team, meaning that even though we sit just below the surface, we have several hours of strenuous caving ahead of us before we can exit the cave.

Just after we have made the decision to leave, a light appears above like the sun emerging from a brooding storm cloud.

‘We’ve done it!’ Vlad shouts down. ‘I’ll put a rope in.’

Soon, we are ascending the rope, enthusiastically greeting Vlad and Stuart (our radio master) and crawling up through the loose debris to the surface. We make it out just in time for sunset, the sun seeping like tree sap from the tops of the mountains. The surface team greet us with dusty faces and a chorus of cheers. It is apparent that they have been working incredibly hard to shift the rocks and get us out in time.

The fading light descends into a night of revelry as we dip into our meagre supplies of cheese and alcohol. We have reached our primary expedition objective – which we thought would take us most of the week – on the very first day, and succeeded in being the first group to complete a through trip of Canada’s deepest cave. What happens next is undecided.

Objective 2: Extending the Hood

The next day, I am paired with Lewis and Oakley to tackle one of our secondary expedition objectives – exploring a different cave, The Hood, that almost certainly connects into the Bisaro cave system. The upper half of the cave is filled by a glacial ice plug. Although the glacier melted long ago on the surface, many of the potholes on the plateau are filled by its shredded skin. As cavers who repeatedly return to the plateau, we witness the continued melting of the ice year on year. Most cave entrances here are not discovered as much as they are revealed by loss.

The day begins slowly, when we realise that the ice plug has melted so much in the last year that we can no longer reach the bolts to rig the rope. After an extensive amount of ‘gardening’ – clearing rocks out from the area where the rope hangs – I start abseiling down the rope, dodging a boulder about the size of a TV that comes flying towards me. We follow a meltwater tunnel that spirals downwards at odd angles. As the newest member of the team, I’m the designated packhorse, and it is my job to carry a length of rebar – a steel rod that repeatedly tries to take my teeth out.

The Pushing Front

We leave our crampons at the end of the ice, grateful to be on solid rock again. Our descent continues until we eventually reach what is known as the ‘pushing front’ – the farthest point that previous groups have reached in the cave, where the exploration can continue.

Whereas some ‘pushing fronts’ consist of open walking passages, ours contains a passage that rises until it is blocked by a ceiling of wedged boulders. This is known as a ‘boulder choke’, where the cave passage continues but has been blocked in one section by a mass of loose boulders. We set to work with various methods of rock-removal: Oakley tries launching large rocks like shotputs at the blockage until they come cascading down. Lewis prefers to prod the boulders with the rebar, while I choose to pull the rocks down with my hands. It is like a less predictable, higher-stakes game of Jenga. As I pull one rock down, an avalanche of boulders races after it, and I narrowly escape being squashed. I fall into a rhythm of jumping forwards, pulling a boulder down, before twisting, spinning and leaping out of the way. The dance requires complete focus: one wrong step might mean you never walk again. Caving demands a strange optimism: the belief that what lies ahead is worth what it takes to reach it.

The process is exhausting. Every time we think we’re about to break through into the passage beyond, more rocks pour out again.

The next day, we return with Vlad and Matt joining the team for a larger effort on the offending boulders. After a few more hours of work, a small window into the untouched void appears.

‘We’re through!’ I squeal, jumping up and down with excitement. ‘Finally! Let’s go!’

The Collapse

Vlad crawls over the rubble first, while the rest of us hold our breath and wait for him to call the rest of us through. The call doesn’t come. Instead, we hear a muttered expletive as a deep rumbling begins. The crescendo ends with a tidal wave of rocks crashing towards us, and we leap out of the firing range. The wave comes to a stop, and we realise with dismay that the window has once again become blocked: but this time with Vlad on the other side.

‘Are you okay?’ I shout at the pile of rocks.

‘I’m fine!’ A muffled voice responds, ‘The rocks are a bit loose here!’

‘Understatement of the year’, I mutter, as we get to work clearing the rocks. Half an hour later, there is once again a small gap connecting our room to the chamber on the other side.

‘Does anyone else want to come through?’ Vlad calls through the hole.

‘Ooh, yes!’ I respond. ‘Coming through now!’

After two days of clearing rocks, desperately trying to break through to new cave, the desire to see ‘what is around the next corner’ takes over me, despite the instability of the surrounding stone. I suppose it’s a caver’s version of summit fever.

As I gingerly crawl through and emerge into the enormous cavern beyond, I realise why we have had so much struggle. Our doorway – or, more accurately, trapdoor – is at the bottom of a large scree slope. Vlad perches on a rock above me, and an aven at least 50 metres in height stretches up behind him. But when I start clambering up towards him, the floor beneath me shifts. I am a salmon pushing upstream through a river of stone. I run up the shifting scree slope like a treadmill as it moves, and leap onto the stable wall of the aven for safety.

‘Oops,’ I comment, ‘it happened again. This is exciting – my first cave-in!’

‘Really?’ Vlad seems shocked. ‘This is your first?’

I get the impression that for those that regularly dig underground in the Rocky Mountains, cave collapses are not a rare occurrence.

‘Yes,’ I laugh, ‘we actually have nice rock back in Yorkshire!’

Once again, the team on the other side start clearing rocks. In the meantime, Vlad and I explore the aven fully, disappointed to find that there is no way on at this level. We conduct a traditional ‘smoke test’ by burning a small amount of toilet paper to see where the smoke goes. It rises upwards, telling us that there is a likely possibility of a connecting passage at the top of the aven.

Unfortunately, without climbing gear, we have no way of reaching it.

After a while, the others confirm that they have cleared the rocks and call us through.

‘How am I meant to get through without destabilising the slope again?’ I ask Vlad.

‘Like a gazelle. You need to jump onto that rock,’ he says, pointing to one in the middle of the scree slope, ‘and then slide through the hole.’

I take a deep breath and launch myself towards the rock. The landing zone is small, and although one foot catches it, the other misses. The slope starts sliding. I move fast, surfing the wave and jumping onto my back to fit through the shrinking hole. Vlad follows close behind me.

As we celebrate being back in relative safety with the rest of the team, I realise that we have achieved the second expedition objective of breaking through the boulder choke. Caving expeditions are unlike mountaineering expeditions, in that we don’t have a ‘summit’ to reach. We have a network of passages of unknown depths and lengths that we explore until we can’t go any further. This year’s breakthroughs in Bisaro Anima and The Hood were possible because of the cumulative hard work of many previous years, and the successes of this year will benefit other expeditions in future.

By the time we emerge, scraped and grinning, the mountain no longer feels like something we are trying to conquer. Instead, it feels like a story that is only just beginning. The Bisaro Anima system remains unfinished, and rather than ending, the breakthroughs on this expedition have simply opened up more possibilities. We leave knowing that we will return in 2026, drawn back not by records or accolades – but by the quiet privilege of moving through places that exist beyond the maps, beyond light, and beyond certainty.

 

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Aila (formerly Anna) Taylor is an outdoor writer and mountain activist. She has previously published in the Guardian, The Independent, Vice and i-D magazines, amongst others. As an avid caver, hiker and cold-water swimmer, Aila is passionate about improving accessibility to the outdoors in addition to spreading awareness about the threats currently facing mountain regions.