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
Grand Coulee Dam interest in irrigation projects. The Bureau of Reclamation, desirous of a major project that would bolster its reputation, was focusing on the Boulder Canyon Project that resulted in the Hoover Dam. Reclamation was authorized to conduct a study in 1923, but the project's cost made federal officials reluctant. The Washington state proposals received little support from those further east, who feared the irrigation would result in more crops, depressing prices. With President Coolidge opposed to the project, bills to appropriate money for surveys of the Grand Coulee site failed. In 1925, Congress authorized a U.S. Army Corps of Engineers study