Siska, also known historically as Cisco, is a locality in the Fraser Canyon of British Columbia, Canada 9.4 kilometres south of the town of Lytton. It is at Siska that the Canadian Pacific and Canadian National Railways switch from one side of the river to the other, due to the impossibility of both railways occupying the same bank of the Fraser due to the narrow and steep terrain. The resulting pair of bridges, with the CNR bridge just upstream of the CPR's, and the CPR's bridge's west foot entering the into the side of , remains one of the most famous images of the CPR's route through British Columbia today and is easily viewable from the adjacent Trans-Canada Highway.