TransCanada pipeline, Natural gas pipeline system in Alberta, Canada

The TransCanada pipeline is a natural gas system of pipes up to 48 inches (1.2 m) in diameter running from Alberta through Saskatchewan, Manitoba, Ontario and Quebec, the longest pipeline in Canada. Where it crosses a field, a white marker sign on a white post with a yellow sleeve carries the TransCanada logo and the warning "This pipeline is buried. Call before you dig."

Construction of this pipeline began in the 1950s following parliamentary approval and faced obstacles from difficult terrain across northern regions. Its completion became a key turning point for regional energy distribution and connected multiple provinces.

The pipeline project generated discussions between Indigenous communities and developers regarding land management and environmental protection across multiple provinces.

You can see sections of this infrastructure from different vantage points, though much of it runs underground and is not directly accessible to the public. Information centers and historical markers in the region provide context about the system and its role.

For one 320-metre stretch on the Canadian Shield, crews drilled 2.4-metre holes into the rock, three abreast at 56-centimetre intervals, while dynamite broke other sections 300 metres at a time. The white marker post in the field carries the TransCanada logo and a warning to call before digging, with an emergency line at 1-888-982-7222.