Spanning the Oldman River Valley near Lethbridge, Alberta, this magnificent steel bridge stretched 5,327 feet (1. Constructed between 1907 and 1909 by the Canadian Pacific Railway, it is the largest railway structure in Canada and the largest of its type in the. On November 3, 1909, the Lethbridge Viaduct officially opened to railway traffic, marking one of the proudest achievements in Canadian rail history. The Golden Gate Bridge in San Francisco, the Eiffel Tower in Paris, and the Sydney Harbour Bridge all define their cities. The Lethbridge Viaduct, or High-Level. The Cisco Bridges are a pair of railroad bridges at Siska (historically known as Cisco) near Lytton, British Columbia, Canada.