Burgess Shale

The Burgess Shale is a paleontological site in Yoho National Park within the Canadian Rockies that preserves marine life from the Middle Cambrian epoch. The rock layers sit on the slopes of mountain peaks such as Wapta Mountain and extend across several outcrops at high elevation.

Charles Walcott came across the fossil layers in 1909 during an expedition and returned regularly in the following years to extract tens of thousands of specimens. Later excavation campaigns starting in the 1960s brought new interpretations about the development of early animal forms.

The name comes from the nearby Burgess Pass and refers to the dark layers of rock on the mountain slope. Hikers today walk through guided routes across rock horizons that formed on the seabed of a tropical ocean.

Access is only possible on a guided hike that takes several hours and follows narrow paths through steep terrain. Because of the high elevation and weather shifts, visitors should bring warm clothing and plenty of water.

The specimens show soft parts like gut tracts and gills that are usually absent in fossils because they normally decay quickly. Some animals possess body plans that cannot be placed into any living animal group.