The Yukon River is a major watercourse of northwestern North America. Over half of the river lies in the U.S. state of Alaska, with most of the other portion lying in and giving its name to Canada's Yukon Territory, and a small part of the river near the source located in British Columbia. The river is 3,700 km (2,300 mi) long and empties into the Bering Sea at the Yukon-Kuskokwim Delta. The average flow is 6,430 m³/s (227,000 ft³/s). The total drainage area is 832,700 km² (321,500 mi²), of which 323,800 km² (126,300 mi²) is in Canada. By comparison, the total area is more than 25% larger than Texas or Alberta.
The longest river in Alaska and the Yukon Territory, it was one of the principal means of transportation during the 1896–1903 Klondike Gold Rush. Paddle-wheel riverboats continued to ply the river until the 1950s, when the Klondike Highway was completed.
Yukon means "great river" in Gwich'in. The river was called Kwiguk, or "large stream", in Yupik. The Lewes River is the former name of the upper course of the Yukon, from Marsh Lake to the confluence of the Pelly River at Fort Selkirk.
The Yukon River has had a history of pollution from gold mining, military installations, dumps, wastewater, and other sources. However, the Environmental Protection Agency does not list the Yukon River among its impaired watersheds , and water quality data from the U.S. Geological Survey shows relatively good levels of turbidity, metals, and dissolved oxygen.
The Yukon River Inter-Tribal Watershed Council, a cooperative effort of 64 First Nations and tribes in Alaska and Canada, has the goal of making the river and its tributaries safe to drink from again by supplementing and scrutinizing Government data.
The generally accepted source of the Yukon River is the Choda Glacier at the southern end of Atlin Lake in British Columbia. Others suggest that the source is Lake Lindeman at the northern end of the Chilkoot Trail. Either way, Atlin Lake flows into Tagish Lake, as eventually does Lake Lindeman after flowing into Bennett Lake. Tagish Lake then flows into Marsh Lake. The Yukon River proper starts at the northern end of Marsh Lake, just south of Whitehorse. Some argue that the source of the Yukon River should really be Teslin Lake and the Teslin River, which has a larger flow when it reaches the Yukon at Hootalinqua. The upper end of the Yukon river was originally known as the Lewes River until it was established that it actually was the Yukon. North of Whitehorse, the Yukon River widens into Lake Laberge, made famous by Robert W. Service's "The Cremation of Sam McGee." Other large lakes that are part of the Yukon River system include Kusawa Lake (into the Takhini River) and Kluane Lake (into the Kluane and then White River).
The river passes through the communities of Whitehorse, Carmacks, (just before the Five Finger Rapids) and Dawson City in the Yukon Territory, and into Circle, Fort Yukon, Stevens Village, Tanana, Ruby, Galena, Nulato, Grayling, Holy Cross, Russian Mission, Marshall, Pilot Station, St. Marys (which is accessible from the Yukon at Pilot Point), and Mountain Village. After Mountain Village, the main Yukon channel frays into many channels, sprawling across the delta. There are a number of communitites after the "head of passes," as the channel division is called locally: Nunum Iqua, Alakanuk, Emmonak, and Kotlik. Of those delta communities, Emmonak is the largest with roughly 760 people in the 2000 census. Emmonak's gravel airstrip is the regional hub for flights.
Volcanoes near the Yukon River, such as Volcano Mountain in the Fort Selkirk Volcanic Field, may have once partly blocked or at least altered the Yukon River by lava flows. Any future activity in this area could disrupt the course of the river and could have serious impacts on people living or working downstream.
Despite its length, there are only four vehicle-carrying bridges across the river:
A car ferry crosses the river at Dawson City in the summer; it is replaced by an ice bridge over the frozen river during the winter. Plans to build a permanent bridge were announced in March 2004, although they are currently on hold because bids came in much higher than budgeted.
There are also 2 pedestrian-only bridges in Whitehorse, as well as a dam across the river and a hydroelectric generating station. The construction of the dam flooded the White Horse Rapids, which gave the city its name, and created Schwatka Lake.
The river flows into several parklands and refuges including: