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.”