High Quality Content by WIKIPEDIA articles! The Big Hill on the Canadian Pacific Railway main line in British Columbia, Canada, was the most difficult piece of railway track on the Canadian Pacific Railway`s route. It was situated in the rugged Canadian Rockies west of the Continental Divide and Kicking Horse Pass. Even though the Big Hill was replaced by the Spiral Tunnels in 1909, the area has long been a challenge to the operation of trains and remains so to this day.