A peak in Yoho National Park towering over the community of Field, British Columbia, just west of Kicking Horse Pass along the Trans-Canada Highway. Mount Stephen is globally renowned for its fossil beds, part of the Burgess Shale formation; a UNESCO World Heritage Site.

Burgess Shale and “stone bugs.” In the 1880s CPR workers discovered what they called “stone bugs” on the mountain’s slopes; trilobites and other marine fossils from the Cambrian period (~505 million years ago). The fossils are exceptionally well-preserved, capturing soft-bodied organisms rarely found elsewhere. Access to the fossil beds is restricted; guided tours (Parks Canada, Burgess Shale Geoscience Foundation) or special research/scramble permits required. Violations carry heavy fines and mandatory court appearances.

Mt. Stephen Trilobite Beds hike. A challenging guided hike (~8 km round-trip, ~800 m gain) winds through forest to the shale beds, where visitors can handle fossils. Reservations mandatory; season typically June–September. Charles Doolittle Walcott’s 1909 Burgess Shale discovery at the Walcott Quarry (above Emerald Lake) built on earlier finds in the region.

Naming and views. Named in 1886 for George Stephen, first president of the Canadian Pacific Railway. The mountain dominates the view from Field and the Trans-Canada; the Kicking Horse River flows at its base. Cathedral Mountain rises directly across the valley. The Spiral Tunnels viewpoints are nearby.