 It extends from Monkman Provincial Park and Tumbler Ridge in the south, to Hudson's Hope and the Williston Lake in the west, to Fort St. John and Charlie Lake in the north.The term is used to mean the whole of the Northeastern Interior past the Rockies, including Fort Nelson and other parts of the Liard drainage, and before W.A.C.Bennett Dam included the upper Peace River through its canyon between Finlay Forks and Hudson's Hope.