Using a geology-based assessment methodology, the U.S. Geological Survey estimated a mean of 40 trillion cubic feet of undiscovered nonassociated gas, a mean of 10.5 billion barrels of undiscovered oil (with 46.6 trillion cubic feet of associated gas), and a mean of 4.0 billion barrels of undiscovered natural gas liquids in the Mackenzie Delta Province of North America, exclusive of the unassessed deep-water portion of the province.