The largest river in the Pacific Northwest region of North America, the Columbia rises in the western slopes of the Rocky Mountains at essentially the same place which gives rise to the Kootenay River. From a point just north of the town of Canal Flats the Columbia flows north while the Kootenay flows south, the two ultimately meeting after long and tortuous journeys at Castlegar, BC. 1,243 miles miles from Canal Flats the Columbia empties into the Pacific at Astoria, Oregon. Along its length are no less than 14 hydroelectric dams, with a great many more (something like 46) on its tributaries.
The first explorer to enter the river was
Robert Gray, in 1792 in the ship
Columbia Rediviva, after which the river was named.
The Methow River was named after the Methow Native Americans (today part of the Confederated Tribes of the Colville Indian Reservation). It rises in the eastern North Cascades, draining an area of about 1,890-square-mile (4,900 sq km), an area inhabited by a population of about 5,000. Much of the river basin is located in national forests and wildernesses, the river flowing through relatively pristine habitats. With an average flow of 1,522 cu ft/s (43.1 m3/s), its minimum is 150 cu ft/s (4.2 m3/s), while its maximum flow during spring runoff can reach 27,200 cu ft/s (770 m3/s).
The Methow joins the Columbia at the south edge of the little town of Pateros. Here, as is the case along much of the river, the Columbia forms a lake behind the Wells Dam, about 12 miles to the south. As is the Columbia, the Methow River is an excellent fly fishing river for Summer Run Steelhead.
The river was named after the Methow Native Americans (today part of the Confederated Tribes of the Colville Indian Reservation). The name "Methow" comes from the Okanagan placename /m?tx?ú/, meaning "sunflower (seeds)". The Native American name for the river was Buttlemuleemauch, meaning "salmon falls river". In 1841 the Wilkes Expedition named the river "Barrier River". Alexander Ross said the native name was Buttle-mule-emauch. In 1811 David Thompson met the tribe living along the river and wrote their name as Smeetheowe. In 1853 George Gibbs called the river Methow or Barrier.
From Wiki
In the photo below, loosely speaking, the water on the near side of the bridge is in the Columbia, while the water on the far side is still in the Methow.