Grand Coulee Dam crane-lifted buckets, each supporting eight tons of concrete. To cool the concrete and facilitate curing, about of piping was placed throughout the hardening mass. Cold water from the river was pumped into the pipes, reducing the temperature within the forms from to . This caused the dam to contract about eight inches in length; the resulting gaps were filled with grout. Until the project began, the stretch of the Columbia River where the dam was to rise was as yet unbridged, making it difficult to move men and materials. In , the Grand Coulee Bridge (a permanent highway bridge) was
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