As national parks go, British Columbia’s Yoho is more compact than most. Driving the Trans-Canada west from the Alberta border, it feels like you’ve already left it behind before you finish reading the “welcome” sign. But if you commit to the turnoff , the jewels you’ll find are among the most precious in all of Canada’s treasured mountain parks. So thought Charles Doolittle Walcott, the American geologist who discovered the Burgess Shale.

Words: Leslie Anthony

Tucked at the base of a massive rock face just off the highway, Cathedral Mountain Lodge immediately feels like the quintessential Rockies hideaway—a cluster of classic log cabins in the forest by a lake. It’s also the starting point for a trip that’s been on my bucket list since reading Stephen J. Gould’s 1981 book Wonderful Life, which details the marvels revealed in this 505 million-year-old formation and the subsequent intrigue surrounding them.

The Burgess Shale, in fact, is the single most important fossil deposit in the world. Containing almost all life forms known from the so-called Cambrian Explosion—an era of numerous new phyla and body plans that seemed to appear “suddenly” in the fossil record—the Burgess has been lionized in literature, fi lm, and even music since its riches began undergoing serious study in the mid-1960s. The deposit’s significance to both evolutionary theory and our understanding of all extant animals groups has remained unmatched in the annals of science. In recent years, the Burgess has again commandeered both scientific and popular consciousness with stunning new interpretations of well-known fossils—some that speak to evolutionary enigmas as central as sight and the perception of colour—as well as discoveries of new life forms, many of which have yet to be described.

All of this is on my mind as I begin the infamous 21-kilometre roundtrip hike to the “Walcott Quarry,” where the Smithsonian Institute scientist and his family excavated fossils for some 20 summers.

Beginning from the parking lot at Takakkwa Falls, we’re soon high enough to see the Daly Glacier whose water feeds it. Above a series of switchbacks, we break onto another bench and the angle of attack lessens as we make our way to Yoho Lake and its historic, century-old Alpine Club of Canada campsite. Leaving the shallow, shimmering waters that are just catching morning sun, we follow a low-angled valley through cool, shadowed forest riven by small streams.

Slowly ascending the flanks of Wapta Peak, occasional breaks in the trees yield glimpses of alpine majesty. Openings soon become more frequent, the views more spectacular. Crossing under a cliff face we watch for rock fall, dive briefly back into trees, then pop out into a large rockslide. With its spectacular overlook of Emerald Lake and its eponymous lodge, the rockslide is a popular lunch spot, as the boldness of a swarm of plump, golden ground squirrels attest.

Shameless crumbhounds, the rodents beg pieces of sandwich and cookie, running over our boots as if these were just more rocks; they’ve done this for generations as Walcott’s early photos document. Afterward, we pass through one last patch of forest before encountering krumholtz—the bonsai, ground-hugging trees that form a welcome mat to the alpine. The world before us reaches for the sky while we tread on what was once ocean bottom fifty fathoms deep.

Over a century after their discovery, the spectacular fossils of the Burgess Shale continue to reveal the deepest secrets of evolution, their very existence a testament to why ignorance of their meaning is so dangerous to society.

Royal Ontario Museum (ROM) scientists have been working new Burgess quarries since the 1970s, making exciting new fi nds annually. A few summers ago, the ROM and Parks Canada launched a Burgess online exhibition as part of the Virtual Museum of Canada, an immersive journey using never-before-seen visuals and stunning animation to bring to life over a century of research and discovery. But the popularity of the Burgess has also made it more vulnerable: several years ago, Parks offi cials chased a pair of Czech thieves, their pockets laden with purloined fossils, across the precipitous slopes.

As a result, we now pass signs warning of a restricted area above the trail before crossing the “discovery point”—a shale talus where Walcott famously got off his horse in 1909 and first noticed the impressions of strange creatures in rock whose origin was eventually traced uphill to the exposure he named the Burgess Shale after a nearby peak. Standing where Walcott made his momentous discovery is spine-tingling for science geeks like myself, and shortly thereafter, we make the fi nal upward turn—switchbacks climbing an open face equivalent to a 41-storey building. By now, anticipation of actually seeing Walcott Quarry has erased any fatigue of ascent, and when we reach it—despite the jarring, solar-powered security camera set-up and steel lock-box in which Parks Canada keeps interpretive material—I can only pause to reflect.

If you know anything of the history of life, neither joy of physical accomplishment nor appreciation of the beauty of the surroundings can surmount the emotion of comprehension that washes over you here. A less familiar and far less tangible feeling, it dwells in the bricolage of broken shale slabs on which you stand—the ungraspable monster of deep time reflected in an odd little riot of life that took place on a muddy ocean floor some half-billion years ago. The range of body plans not only includes most of the invertebrate phyla with which we’re familiar, but also forms that represent opposite extremes: on the one hand there are those creatures—some truly bizarre—that lost the evolutionary lottery and blinked out of existence forever; on the other hand are found the humble beginnings of our own heritage—primitive chordates that would, in a hundred million years or so, give rise to the vertebrates.

Over a century after their discovery, the spectacular fossils of the Burgess Shale continue to reveal the deepest secrets of evolution, their very existence a testament to why ignorance of their meaning is so dangerous to society. That’s because to stand in a place like the Walcott Quarry and truly understand its significance and connection to ourselves is to let go of all prejudice, imperialism and appetite for war, and to abandon notions that artificial constructs like “the economy” carry any meaning whatsoever. Instead, the long-vanished organic diversity of the Burgess casts all of humanity—which came onto the scene a mere geological blink of an eye ago—as sharing a razor- thin slice of time as a single species that may or may not similarly disappear.