One very unique experience offered by the Canadian Rockies is the chance to set foot on one of the world's best known fossil sites, a UNESCO World Heritage Site in itself, led by a Parks Canada Guide. Imagine walking into a massive burial of prehistoric creatures 500 million years old, where fossils are so abundant that you CANNOT possibly take a step without stepping on some animal more ancient than any dinosaur. That is the uniqueness of the Burgess Shale fossil beds at Yoho National Park.
To put into context how famous the Burgess Shale is: I still remember reading about it in my high school science textbook, many years ago, where it probably discussed the Cambrian Explosion. In fact if you walk into a Cambrian (500 million years ago) fossil exhibit at any major natural history museum in North America, there's a good chance that many specimens came from Burgess Shale. This is the kind of place you read about in National Geographic, and I couldn't resist when I heard about this guided hike into the site, located just 2 hour's drive from Banff.
At the time of writing Parks Canada offers two different guided hikes to what is collective called the Burgess Shale fossil sites. Both hikes must be carried out under the supervision of a licensed guide, and both fossil sites are under constant video surveillance to ensure that no fossil is removed by visitors. Walcott Quarry is a 20km round-trip, 10 hour hike; Mount Stephen is considerably shorter (6km round-trip in 7 hours) but very steep towards the top. We signed up for the short and steep hike up Mount Stephen, thinking it would be relatively easier. Well ... it wasn't easy, as we're about to find out.
The hike has to be booked at least a day in advance, online or at the Visitor Centre in the town of Field, at the cost of CAD$55 as of 2011. Our hike started out very early, 7:30am in fact, in the town of Field where our guide Claudia assessed the group and gave a great introduction on the Burgess Shale and our upcoming hike. The atmosphere turned serious when she took out a large collection of old hiking/ski poles and made very sure that each of us would carry a pair before we set out. Everyone knew then that this would be no easy hike.
It was all uphill from the town of Field, with close to 800m of elevation gain to be covered in about 3 hours. The first 2.5 hours of the trail cut a winding path through a pristine forest of cedars and firs, with the occasional view point down towards Field. The steepness did not yet require hiking poles, which made us a little apprehensive. Somewhere along the trail we came across this serious-looking sign that we're about to enter a restricted area, and most importantly, that the removal of fossil is illegal.
In the final 45 minutes the trail became increasingly steep, to the point where we had to scramble with our hands at times (just look at the 40-degree slope in the picture's background). It was then apparent that poles would become crucial later when working our way downhill. But for now, we had arrived at the entrance of the famous trilobite beds of Mount Stephen.
The whole fossil site was a steep, barren shale quarry, situated right at the treeline at an elevation of 2000m. 1200m below the site lies the Kicking Horse River valley and the town of Field, and anywhere above the site is mountain goat territory. This is high, high up in the Canadian Rockies, and it's difficult to imagine that it used to be an ocean floor, back in the age of these fossilized creatures.
Claudia gave a lecture on paleontology at the only relatively flat spot at the site. At about 5 metres in diameter this was the only possible landing spot for helicopters in case someone in the group could not make it down by his/her own power. And given the steepness of the trail, that was a real possibility.
This was the gold mine that everyone in the group came to see -- a quarry of countless prehistoric fossils, all lying unclaimed at our feet. Our guide did remind us again though, that taking anything out of the quarry could get us prosecuted. Practically every piece of shale here contained the body or imprint of some prehistoric creature, and it was impossible to walk anywhere without stepping on, and possibly breaking, some fossil.
These beautifully complex trilobite shells were everyone's favorite fossil at the beginning. But after 30 minutes they had become so commonly found that one can hardly look anywhere without coming across a few new ones. In fact I personally probably broke a few just by walking around the quarry.
The discovery of fossils like this is what makes Burgess Shale one of the world's most important fossil sites. The preservation of shells and bones is common; having soft body parts and tissues preserved as fossils is very, very rare. Burgess Shale became a UNESCO World Heritage Site particularly for its excellent preservation of soft-bodied marine animals, such as this catepillar-like Aysheaia here.
After an hour's digging and lunch it was time to take the same trail downhill back towards town. This was the toughest part of the hike, starting with 30 minutes of descending a 40-degree steep narrow path of nothing but loose shale and eroded soil. See the slope in the background of the picture -- it was really that steep.
To make matters worse, two of the old hiking poles we borrowed weren't properly locking in position, making my wife very nervous on her way down. Thankfully our guide Claudia was kind enough to exchange one of her own poles with my wife, and to patiently teach my wife the proper way of using her poles as anchors on the downhill hike. We definitely wouldn't have made it safely downhill without her help.
At the end I kept wondering whether it would have been wiser to join that 20km roundtrip hike to Walcott Quarry. Yes it's much longer, but the elevation gain would be more gradual and the trail probably wasn't quite as steep. But we certainly have no regrets -- we were granted a rare opportunity to hike into one of the world's premier fossil sites, and came away with some great memories and a good story to tell. And even without the fossils, it's still a wonderful hike to a great panoramic vista at the top. It's an experience I fully recommend to my friends ... as long as they're reasonably fit and are not afraid of steep trails ...
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