Fraser River

The Fraser River is the longest river within British Columbia, Canada, rising at Fraser Pass near Blackrock Mountain in the Rocky Mountains and flowing for , into the Strait of Georgia just south of the City of Vancouver. It is the 11th longest river in Canada. The river's annual discharge at its mouth is or , and it discharges 20 million tons of sediment into the ocean.
Naming.
The river is named after Simon Fraser, who led an expedition in 1808 on behalf of the North West Company from the site of present-day Prince George almost to the mouth of the river.
The river's name in the Halqemeylem (Upriver Halkomelem) language is ', often seen archaically as Staulo, and has been adopted by the Halkomelem-speaking peoples of the Lower Mainland as their collective name, . The river's name in the Dakelh language is '. The "Tsilhqot'in" name for the river, not dissimilar to the "Dakelh" name, is , meaning Sturgeon "()" River "()".
Course.
The Fraser drains a area. Its source is a dripping spring at Fraser Pass in the Canadian Rocky Mountains. The river then flows north to the Yellowhead Highway and west past Mount Robson to the Rocky Mountain Trench and the Robson Valley near Valemount. After running northwest past 54° north, it makes a sharp turn to the south at Giscome Portage, meeting the Nechako River at the city of Prince George, then continues south, progressively cutting deeper into the Fraser Plateau to form the Fraser Canyon from roughly the confluence of the Chilcotin River, near the city of Williams Lake, southwards. It is joined by the Bridge and Seton Rivers at the town of Lillooet, then by the Thompson River at Lytton, where it proceeds south until it is approximately north of the 49th parallel, which is Canada's border with the United States.
From Lytton southwards it runs through a progressively deeper canyon between the Lillooet Ranges of the Coast Mountains on its west and the Cascade Range on its east. Hell's Gate, located immediately downstream of the town of Boston Bar, is a famous portion of the canyon where the walls narrow dramatically, forcing the entire volume of the river through a gap only 35 metres (115 feet) wide. An aerial tramway takes visitors out over the river. Hells Gate is visible from Trans-Canada Highway 1 about south of the tramway. Simon Fraser was forced to portage the gorge on his trip through the canyon in June 1808. 
At Yale, at the head of navigation on the river, the canyon opens up and the river widens, though without much adjoining lowland until Hope, where the river then turns west and southwest into the Fraser Valley, a lush lowland valley, and runs past Chilliwack and the confluence of the Harrison and Sumas Rivers, bending northwest at Abbotsford and Mission.
The Fraser then flows past Maple Ridge, Pitt Meadows, Port Coquitlam, and north Surrey. It turns southwest again just east of New Westminster, where it splits into the North Arm, which is the southern boundary of the City of Vancouver, and the South Arm, which divides the City of Richmond from the City of Delta to the south. Richmond is on the largest island in the Fraser, Lulu Island and also on Sea Island, which is the location of Vancouver International Airport, where the Middle Arm branches off to the south from the North Arm. The far eastern end of Lulu Island is named Queensborough and is part of the City of New Westminster. Also in the lowermost Fraser, among other smaller islands, is Annacis Island, an important industrial and port area, which lies to the southeast of the eastern end of Lulu Island. Other notable islands in the lower Fraser are Barnston Island, Matsqui Island, Nicomen Island and Sea Bird Island. Other islands lie on the outer side of the estuary, most notably Westham Island, a wildfowl preserve, and Iona Island, the location of the main sewage plant for the City of Vancouver.
After 100 kilometres (about 60 mi), the Fraser forms a delta where it empties into the Strait of Georgia between the mainland and Vancouver Island. The lands south of the City of Vancouver, including the cities of Richmond and Delta, sit on the flat flood plain. The islands of the delta include Iona Island, Sea Island, Lulu Island, Annacis Island, and a number of smaller islands. While the vast majority of the river's drainage basin lies within British Columbia, a small portion in the drainage basin lies across the international border in Washington in the United States, namely the upper reaches of the tributary Chilliwack and Sumas rivers. Most of lowland Whatcom County, Washington is part of the Fraser Lowland and was formed also by sediment deposited from the Fraser, though most of the county is not in the Fraser drainage basin.
Similar to the Columbia River Gorge east of Portland, Oregon, the Fraser exploits a topographic cleft between two mountain ranges separating a more continental climate (in this case, that of the British Columbia Interior) from a milder climate near the coast. When an Arctic high-pressure area moves into the British Columbia Interior and a relatively low-pressure area builds over the general Puget Sound and Strait of Georgia region, the cold Arctic air accelerates southwest through the Fraser Canyon. These outflow winds can gust up to and have at times exceeded . Such winds frequently reach Bellingham and the San Juan Islands, gaining strength over the open water of the Strait of Juan de Fuca.
The estuary at the river's mouth is a site of hemispheric importance in the Western Hemisphere Shorebird Reserve Network.
Discharge.
The Water Survey of Canada currently operates 17 gauge stations that measure discharge and water level along the majority of the mainstem from Red Pass just downstream of Moose Lake in the Mount Robson Provincial Park, to Steveston in Vancouver at the river mouth. With an average flow at the mouth of about , the Fraser is the largest river by discharge flowing into the Pacific seaboard of Canada and the fifth largest in the country. The average flow is highly seasonal; summer discharge rates can be ten times larger than the flow during the winter.
The Fraser's highest recorded flow, in June 1894, is estimated to have been at Hope. It was calculated using high-water marks near the hydrometric station at Hope and various statistical methods. In 1948 the Fraser River Board adopted the estimate for the 1894 flood. It remains the value specified by regulatory agencies for all flood control work on the river. Further studies and hydraulic models have estimated the maximum discharge of the Fraser River, at Hope during the 1894 flood, as within a range of about .
History.
On June 14, 1792, the Spanish explorers Dionisio Alcalá Galiano and Cayetano Valdés entered and anchored in the North Arm of the Fraser River, becoming the first Europeans to find and enter it. The existence of the river, but not its location, had been deduced during the 1791 voyage of José María Narváez, under Francisco de Eliza.
The upper reaches of the Fraser River were first explored by Sir Alexander Mackenzie in 1793, and fully traced by Simon Fraser in 1808, who confirmed that it was not connected with the Columbia River.
In 1828 George Simpson visited the river, mainly to examine Fort Langley and determine whether it would be suitable as the Hudson's Bay Company's main Pacific depot. Simpson had believed the Fraser River might be navigable throughout its length, even though Simon Fraser had described it as non-navigable. Simpson journeyed down the river and through the Fraser Canyon and afterwards wrote "I should consider the passage down, to be certain Death, in nine attempts out of Ten. I shall therefore no longer talk about it as a navigable stream". His trip down the river convinced him that Fort Langley could not replace Fort Vancouver as the company's main depot on the Pacific coast.
Much of British Columbia's history has been bound to the Fraser, partly because it was the essential route between the Interior and the Lower Coast after the loss of the lands south of the 49th Parallel with the Oregon Treaty of 1846. It was the site of its first recorded settlements of Aboriginal people ("see" Musqueam, , St'at'imc, Secwepemc and Nlaka'pamux), the route of multitudes of prospectors during the Fraser Canyon Gold Rush and the main vehicle of the province's early commerce and industry.
In 1998, the river was designated as a Canadian Heritage River for its natural and human heritage. It remains the longest river with that designation.
Uses.
The Fraser is heavily exploited by human activities, especially in its lower reaches. Its banks are rich farmland, its water is used by pulp mills, and a few dams on some tributaries provide hydroelectric power. The main flow of the Fraser has never been dammed partly because its high level of sediment flows would result in a short dam lifespan, but mostly because of strong opposition from fisheries and other environmental concerns. In 1858, the Fraser River and surrounding areas were occupied when the gold rush came to the Fraser Canyon and the Fraser River. It is also a popular fishing location for residents of the Lower Mainland.
The delta of the river, especially in the Boundary Bay area, is an important stopover location for migrating shorebirds.
The Fraser Herald, a regional position within the Canadian Heraldic Authority is named after the river.
Fishing.
The Fraser River is known for the fishing of white sturgeon, all five species of Pacific salmon (chinook, coho, chum, pink, sockeye), as well as steelhead trout. A typical white sturgeon catch can average about . 
A large white sturgeon weighing an estimated and measuring was caught and released on the Fraser River in July 2012, but it was reportedly measured nose to tip of tail, not nose to fork as is the officially recognized method for accurate measurement of this species. Thus the "reported" length of this fish, and its estimated weight, were likely greater than what its actual measurements would have been if standard data collection had been utilized in this case. Regardless of this discrepancy, landing large sturgeon like this is reasonably uncommon, however fish nearing or achieving this size are caught on rod and reel in the Fraser river virtually every year, and reports of even larger fish being lost occur with fair regularity. A variety of guiding outfits throughout the Fraser valley and lower mainland offer services to pursue this magnificent sportfish.
Flooding.
After European settlement, the first disastrous flood in the Fraser Valley occurred in 1894. With no protection against the rising waters of the Fraser River, Fraser Valley communities from Chilliwack downstream were inundated with water. In the 1894 floods, the water mark at Mission reached .
After the 1894 flood, a dyking system was constructed throughout the Fraser Valley. The dyking and drainage projects greatly improved the flood problems, but unfortunately over time, the dykes were allowed to fall into disrepair and became overgrown with brush and trees. With some dykes constructed of a wooden frame, they gave way in 1948 in several locations, marking the second disastrous flood. Flooding since 1948 has been minor in comparison.
1948 flood.
1948 saw massive flooding in Chilliwack and other areas along the Fraser River. The high-water mark at Mission rose to . The peak flow was about 15,600 cubic meters per second.
Causes.
Cool temperatures in March, April, and early May had delayed the melting of the heavy snowpack that had accumulated over the winter season. Several days of hot weather and warm rains over the holiday weekend in late May hastened the thawing of the snowpack. Rivers and streams quickly swelled with spring runoff, reaching heights surpassed only in 1894. Finally, the poorly maintained dike systems failed to contain the water.
At the height of the 1948 flood, stood under water. Dykes broke at Agassiz, Chiliwack, Nicomen Island, Glen Valley and Matsqui. When the flood waters receded a month later, 16,000 people had been evacuated, with damages totaling $20 million, about $210 million in 2010 dollars.
Later flooding.
Due to record snowpacks on the mountains in the Fraser River catch basin which began melting, combined with heavy rainfall, water levels on the Fraser River rose in 2007 to a level not reached since 1972. Low-lying land in areas upriver such as Prince George suffered minor flooding. Evacuation alerts were given for the low-lying areas not protected by dikes in the Lower Mainland. However, the water levels did not breach the dikes, and major flooding was averted.
Tributaries.
Tributaries are listed from the mouth of the Fraser and going up river.