The original Trans Mountain Pipeline (Line 1) was constructed in 1952 with additional infrastructure added in 2008

It is currently in operation and transports crude oil and refined petroleum products from near Edmonton, Alberta to Burnaby, B.C., with a capacity of about 300,000 barrels of petroleum products each day.

The existing Trans Mountain Pipeline traverses 1,150 kilometres and crosses numerous communities and traditional lands.

The Trans Mountain Expansion Project (TMEP) involves the installation of new pipeline (roughly in parallel to the existing Line 1) and associated facilities, allowing for an increase in shipping capacity.

The new pipeline will have a 36-inch diameter and will transport 590,000 barrels per day of heavy oil from the Alberta oil sands. It spans 980 km of important cultural territory. The TMEP impacts rights and title holders along the pipeline route and as such, consultation and accommodation was required.

On June 18, 2019, the Government of Canada approved the TMEP. The courts have affirmed the legal duty to consult with Indigenous people on the project has been met.