The above Cambrian map is from Dr. C. Scotese’s Paleomap project. Note that Laurentia is the Paleo-Continent of North America. In other words, Laurentia is an early version of North America. The outline of present day North America is in white. It may be a little bit hard to recognize because the continent is turned clockwise by 90 degrees.
The world was a very different place in the Cambrian time period, when the animals of the Burgess Shale were thriving in tropical oceans. The Cambrian world map looked very different to that of today. The majority of the land mass was located in the southern hemisphere. Ancestral North America (Laurentia) was located near the equator and was a separate continent from the supercontinent (Gondwana). During the Cambrian, the Burgess Shale sites lay just north of the equator, far offshore from Laurentia. Sediments (mud, silt) were deposited (laid down) on the bottom of this ancient tropical ocean. These sediments eventually formed the rocks that we now see in Yoho National Park.