Originally Posted by Charlatan

It is the Pembina River Viaduct and The Yellowhead Highway Bridge... which is near Entwhistle, Alberta.

Originally Posted by Wikipedia

The Pembina River Viaduct

The Grand Trunk Pacific railway bridge whose construction caused Entwistle to spring up is still in operation today. It is a vital part of the Canadian National Railway main line, connecting Canada to the Pacific Ocean. An average of 20 trains travel across it per day. The trestle itself is 910 feet long and 214 feet high. It was the first steel railway trestle built in Western Canada. It is currently the second-highest railway trestle in Western Canada.

Construction on the bridge began in 1908. As there were no cranes big enough to carry steel back then, a massive false bridge and scaffolding was built out of wood. The steel bridge itself was completely pre-fabricated in Scotland. The Scottish engineers assembled the bridge in Scotland, ran their tests on it, and then carefully dismantled it. The bridge was shipped piece-by-piece across the Atlantic, and brought out to Entwistle on the railway. The pieces began arriving in 1909, and the steel bridge was slowly assembled. The engineers’ measurements were so accurate, that no modifications were needed on site. [2]

As the steel structure was laid in place, the wooden scaffolding and false bridge were gradually dismantled. Construction was completed in 1910. As it nears the end of its first century of use, it has required no major repairs; only routine maintenance.
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The Yellowhead Highway Bridge

Equally impressive is the Yellowhead Highway Bridge, running parallel to the Pembina River Viaduct.
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The bridge is 207 feet high and approximately 900 feet long. It cost $1.7 million. When construction was finished in 1962, it was the highest highway bridge in Alberta.