Koyukuk

enUK

Koyukuk

 

a river in central Alaska (USA), a right tributary of the Yukon River. It is formed by the confluence of the John, Wild, and Middle Fork Koyukuk rivers, which flow from the Endicott Mountains. Length from the confluence of its sources, 740 km; from the source of Middle Fork, 1,000 km. In its upper half, the Koyukuk’s course flows through mountainous country; its lower half flows through a marsh-ridden intermontane depression. The river is fed by snow and rain. It floods in summer. The average flow rate of water at the village of Hughes (in the river’s middle course) is approximately 400 cu m per sec. The Koyukuk is covered with ice from October through May. It is navigable for small river vessels along its entire course.