Coast Mountains, range, W British Columbia and SE Alaska, extending c.1,000 mi (1,610 km) parallel to the Pacific coast, from the mountains of Alaska near the Yukon border to the Cascade Range near the Fraser River. Mt. Waddington (13,260 ft/4,042 m) is the highest peak. The geologically complex range, composed mainly of metamorphic rocks, slopes steeply to the Pacific Ocean, where the shoreline is deeply indented by fjords. The Coast Mts. have been heavily eroded by mountain glaciers; numerous rivers, including the Fraser, the Skeena, and the Stikine, have cut deep gorges across the range. The average annual precipitation of c.90 in. (230 cm) makes the region one of the wettest parts of Canada. Its slopes are heavily forested, and lumbering is important. In the Coast Mts. is Kemano, one of Canada's largest hydroelectric plants. The Coast Mts. are sometimes confused with the geologically distinct Coast Ranges.