The Fraser Plateau and Basin Complex is an ecoregion defined by the World Wildlife Fund. It encompasses the middle reaches of the watershed of the Fraser River as it traverses the northern part of the Interior Plateau of British Columbia. The WWF ecoregion is similar in description to two of the ecoregions within Environment Canada's Montane Cordillera Ecozone: The Fraser Basin and the Fraser Plateau. Much of the Fraser Plateau is underlain by volcanic rocks, with steep escarpments along rivers and creeks and almost flat upper surfaces.