Nespelem River before the river empties into the Columbia River. This reach of the Columbia River is several miles below Grand Coulee Dam and many miles above Chief Joseph Dam. The impounded Columbia River behind Chief Joseph Dam, into which the Nespelem River flows, is called Rufus Woods Lake. Nespelem River The Nespelem River is a northern tributary of the Columbia River, in the U.S. state of Washington. It is completely contained within Okanogan County and the Colville Indian Reservation. The name "Nespelem" is said to come from the Indian word "nesilim", meaning "flat land". The Nespelem River originates in eastern Okanogan
Columbia River known as the Grand Coulee. After the floods, the river found its present course, and the Grand Coulee was left dry. The construction of the Grand Coulee Dam in the mid-20th century impounded the river, forming Lake Roosevelt, from which water was pumped into the dry coulee, forming the reservoir of Banks Lake. The river flows past The Gorge Amphitheatre, a prominent concert venue in the Northwest, then through Priest Rapids Dam, and then through the Hanford Nuclear Reservation. Entirely within the reservation is Hanford Reach, the only US stretch of the river that is completely free-flowing, unimpeded by dams