Connaught Tunnel is under Mount Macdonald.
Connaught Tunnel . Trains now predominantly travel east through the Connaught Tunnel and west through the Mount Macdonald Tunnel . The Mount Macdonald Tunnel , located in the vicinity of Rogers Pass in the Selkirk Mountains of British Columbia , Canada , is a railway tunnel constructed through Mount Macdonald by the Canadian Pacific Railway ( CPR ) . The Mount Macdonald Tunnel supplements the nearby Connaught Tunnel that the CPR opened in 1916 .