The Trans Mountain Pipeline System, or simply the Trans Mountain Pipeline (TMPL), is a multiple product pipeline system which carries crude and refined products from Edmonton, Alberta, to the coast of British Columbia, Canada.
The corporation was created in 1951, construction began in 1952, and operations commenced in 1953. It is the only pipeline to run between these two areas. The construction of a second pipeline between Hinton, Alberta, and Hargreaves, British Columbia, running adjacent to the existing line, was completed in 2008. In 2013, a project to loop the existing Trans Mountain pipeline—the Trans Mountain Expansion Project—was proposed to the Canadian National Energy Board. The project was 98% complete, as of 23 January 2024, and began operations on 1 May 2024. The expansion, which runs roughly parallel to the existing pipeline, increased capacity from 300,000 to 890,000 barrels per day (48,000–141,000 m/d), at a cost of C$53 billion.