The Cariboo Mountains are the northernmost subrange of the Columbia Mountains, which run down into the Spokane, Washington area of the United States and include the Selkirks, Monashees and Purcells. The Cariboo Mountains are entirely within the province of British Columbia, Canada. The range is 7,700 km² (c. 2,975 sq mi) in area and about 245 km in length (SE-NW) and about 90 km at its widest (SW-NE).