is the fourth highest waterfall in Canada. It owes its foundation to the deposits of volcanic rock that were placed down in the wide valley of the Murtle River. Layer upon layer of fresh lava created flat areas, over which enormous floods flowed during the last ice age. These floods shaped the upright cliff in the lava flows over which the river now flows. The protection of Helmcken Falls was one of the major causes for the development of Wells Gray Provincial Park. As a result, if it had not been for the volcanic eruptions, it is not likely that such a large wilderness region would have been made. Water The Fraser River forms an important transportation corridor when it drains much of central and southern British Columbia flowing to the Pacific Ocean. Other major rivers include the upper Columbia River and the Kootenay River. In northern B.C. the Stikine, Nass and Skeena Rivers flow toward the Pacific Ocean, and Peace River flows northeast toward the Arctic Ocean. Hydroelectric resources in B.C. are highly developed, and pulp and paper and lumber mills are common throughout the province. The Fraser, Nass, and Skeena Rivers have not been dammed in order to protect the salmon runs on them. Rivers and their valleys have for a long time provided routes through the mountains for people in B.C. Long, narrow lakes are found throughout the valleys of the Southern and Central Interior. Among these are Atlin, Kootenay, Okanagan, Quesnel, and Shuswap Lakes. Several high dams have impounded large reservoir lakes like Kinbasket Lake, particularly on the Columbia (see Hydroelectric dams on the Columbia River) and Peace Rivers. Williston Lake, on the Peace River, is the province's largest body of freshwater. Source Statistics Canada Source Environment Canada Sources Statistics Canada, WLD, anglersatlas.com Climate Because of the many mountain ranges and rugged coastline, British Columbia's climate varies dramatically across the province. Coastal southern British Columbia has a mild, rainy oceanic climate, influenced by the North Pacific Current, which has its origins in the Kuroshio Current. Hucuktlis Lake on Vancouver Island receives an average of of rain annually, and some parts of the area are even classified as warm-summer Mediterranean, some of the northernmost occurrences in the world. In Victoria, the annual average temperature is , the warmest in Canada. Due to the blocking presence of successive mountain ranges, the climate of some of the interior valleys