The Fraser River, the longest river in British Columbia (1,375 km), with a drainage basin of 234,000 km2, rises in Fraser Pass on the western slopes of the Rocky Mountains in the southeast corner of Mount Robson Provincial Park. It first flows slowly northwest in meandering channels along the flat valley floor of the Rocky Mountain Trench to Prince George, BC, where it bends to a southward course. The gravel banks of the Fraser then increase in height to 50–100 m, where the river has cut down into the glacial deposits of the central Interior Plateau; the river's velocity of flow increases south of Prince George as it is joined by several tributaries, the largest being the Nechako River from the northwest.
The Fraser enters the Fraser Canyon south of Quesnel, where it is joined by the Chilcotin River from the west. Here the river has cut down 300–600 m into the bedrock of the Interior Plateau. In this middle section the Fraser is joined by other large tributaries such as the Quesnel and Thompson rivers from the east and the West Road River from the west. At Hell’s Gate, south of Boston Bar, the river narrows to 35 m. At the southern end of the canyon, near Yale, the river flows between the north end of the Cascade Mountains to the east and the Coast Mountains to the west.
The Fraser River bends westward at Hope, BC, and the slope of the stream flattens out. The valley then broadens into a delta that is about 50 km wide, where the river empties into the Strait of Georgia at Vancouver. The southwestern part of the Fraser delta is in Washington State. Water flowing through the Fraser River comes primarily from melting snow, with highest flows from May to July and lowest flows from January to March.
Flora and Fauna
The Fraser River and its tributaries are home to one of the most productive salmon fisheries in the world, supporting five species of Pacific salmon — sockeye, coho, chum, Chinook and pink. Salmon eggs hatch in fresh water, but salmon spend most of their lives in the ocean before migrating back upstream to spawn.19 Numerous other species of fish are found in the river, including rainbow and brook trout, river and Pacific lamprey, eulachon, surf and longfin smelt, northern squawfish, peamouth chub, redside shiner, longnose dace, several species of sucker, and prickly sculpin.
The Fraser River basin includes alpine tundra, coniferous forest, grasslands and coastal rainforest,and therefore supports a wide diversity of vegetation. Dominant species include lodgepole pine, white spruce, trembling aspen, Douglas fir, Engelmann spruce, alpine fir and western hemlock, with grassland found in arid regions. A variety of wildlife species inhabits this region, including woodland caribou, black-tailed deer, moose, bighorn sheep, mountain goat, coyote, wolf, black and grizzly bear, muskrat, grouse and Steller’s jay.
One of the greatest threats to forest environments in the Fraser River basin is the ongoing mountain pine beetle epidemic. In 2007, for example, mountain pine beetles had affected more than 8.8 million hectares of the region, with the Cariboo-Chilcotin and Upper Fraser being the hardest hit.Mountain pine beetles target and kill mature trees by tunnelling through the bark and feeding on the wood layers beneath. The most abundant pine in BC, the lodgepole pine, has been hardest hit. The needles on the dead trees turn red, and vast areas of red forest can be seen in the Fraser River basin. Loss of living trees, through mountain pine beetle infestations as well as clear-cut forestry practices, increases the rate of rainfall and snowmelt runoff, in turn affecting the flow of the Fraser River. The rate of rainfall reaching the ground increases because trees and underbrush are no longer there to intercept precipitation, while snowmelt increases, since without trees, solar radiation can better reach the ground.
Pulp and paper mills located at Prince George and Quesnel, adjacent to the Fraser River, are sources of contamination; although contamination downstream of these mills still exists, changes to bleaching processes in the 1990s dramatically improved water quality. Other sources of contamination originate as urban and agricultural runoff. Additionally, industrial mineral, coal, and metal mining operations exist in the Fraser River basin, all of which are potential sources of pollution.On 4 August 2014, a breach of the tailings pond dam at the Mount Polley mine sent 8 million m3 of contaminants into Hazeltine Creek, Polley Lake and Quesnel Lake in the Fraser River basin.The waste water contained cobalt, nickel, antimony, arsenic, lead, selenium, mercury and cadmium. The disaster had a substantial impact on the local aquatic environment and may have long-term impacts on salmon spawning in the area.
First Nations have lived in the Fraser River basin for more than 10,000 years, relying on the river for its abundant resources and transportation routes. Salmon was particularly important for the diet and cultural traditions of First Nations along the Fraser. There are three primary cultural areas — the Coast Salish near the mouth of the Fraser; the Plateau, including Nlaka’pamux, Okanagan (also known as the Syilx), Secwepemc, St’át’imc and Tsilhqot’in in the central Fraser; and the Subarctic people, including the Dakelh, Sekani and Wet’suwet’en in the Upper Fraser. In addition to salmon, First Nations caught sturgeon, cod, trout and eulachon using advanced fishing tools such as spears, nets, hooks and traps, and hunted deer, moose, mountain goat, marmot, black bear and beaver.
In 1808, Simon Fraser, the man for whom the river is named, became the first European to travel the majority of the Fraser River. A fur trading post was set up at Fort Langley on the Lower Fraser in 1827; however, the Upper Fraser had been explored previously, with fur trade posts established at Fraser Lake in 1806 and Fort George in 1807. Little use was made of the Central Fraser, because of its turbulent currents, until the discovery of gold on sandbars south of Yale set off the Fraser River Gold Rush in 1858. The Cariboo Gold Rush, which followed to the north, brought the first narrow road (Cariboo Road), carved into the canyon walls, and later the Canadian Pacific Railway followed the gash of the Thompson-Fraser rivers as the only low-level route through the Coast-Cascade mountain barrier to southwestern BC. This spark of European settlement disrupted and displaced First Nations communities, depleted salmon stocks, and introduced diseases such as measles, influenza, scarlet fever and smallpox, which decimated First Nations populations.
In 1998, the Fraser River was designated as a Canadian Heritage River based on its vast cultural and natural heritage, including geologic formations, rich First Nations history, and importance to European settlement.