The Fraser Canyon is a major landform of the Fraser River where it descends rapidly through narrow rock gorges in the Coast Mountains en route from the Interior Plateau of British Columbia to the Fraser Valley. Colloquially, the term "Fraser Canyon" is often used to include the Thompson Canyon from Lytton to Ashcroft, since they form the same highway route which most people are familiar with, although it is actually reckoned to begin above Williams Lake at Soda Creek Canyon near the town of the same name.