On June 18, 2003 Imperial Oil Resources, on behalf of the Producers Group, announced TransCanada's involvement in the Mackenzie Valley pipeline. If development of this pipeline goes ahead, it would connect with TransCanada's system in Northern Alberta.

TransCanada is providing funding for the Aboriginal Pipeline Group (APG) for the project definition phase of the Mackenzie Gas Project. The APG was formed in 2000 to represent the ownership interest of the Aboriginal peoples of the Northwest Territories in the proposed Mackenzie Valley pipeline. In exchange for this funding, TransCanada earns a number of acquisition and expansion rights together with a financial return if the project goes ahead.

The Mackenzie Gas Project includes the Mackenzie Valley pipeline and gas gathering system, liquids extraction, liquids pipeline and field developments. The proponents of the project include Imperial Oil Resources, ConocoPhillips Canada, Shell Canada Limited, ExxonMobil Canada (the Producers) and the APG.