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Grand Coulee Dam

One may say that the site of Grand Coulee Dam was determined centuries ago. Lava, hissing and boiling, fought with angry waters, cooled, and bore plant life; then lava came again, repeating the same cycle in successive periods, until seven flows had been recorded in the dark porous rock, streaked with reds and greens, of the high coulee walls. Centuries passed, and then a great ice sheet, which scientists say was 4,000 feet thick, descended from the North. Tearing the earth’s surface, pushing huge quantities of boulders and gravel before it, the ice sheet moved southward, melting, and forming a mighty flood. The flood boiled over the river’s channels, grinding out great gorges and forming new channels. Temporarily, at the present site of Coulee Dam, the river was diverted from its regular course and roared south across the gently sloping tableland, forming what is now known as the Grand Coulee, a chasm over 50 miles long, 800 feet deep and from 2 to 5 miles wide. It then plunged over the great cataract now known as Dry Falls and rejoined the old channel further to the south. When the great ice mass finally melted away, the river resumed its age-old course, leaving the Grand Coulee high and dry. The dam was irrigated 1,300,000 acres, which had long been desert land.

There were other important factors that determined the site. The junction of the river with the coulee has a natural dam foundation of hard, white granite, over 800 feet deep. Nature also left a measureless quantity of gravel on the bank of the valley. Most important of all was the fact that here, bordering a river whose discharge is more regular throughout the entire year than any other river of the land, and whose runoff is five times as great as that of the Colorado River at Boulder Dam, is a vast stretch of arid land which needs to be irrigated—an authority on reclamation called it “one of the most fertile bodies of irrigable land in this or any other country.”

Despite the natural advantages of the site, construction involved many problems never before confronted by engineers. It was necessary to build a massive structure larger than any ever built before, which would withstand the pressure of water 355 feet deep across a width of 4,300 feet. The Columbia, flowing as fast as 14 miles an hour, had to be diverted from its ancient channel and made to flow through a man-made passage while the foundations were being laid. By means of a tremendous belt conveyor 15,000,000 cubic yards of earth and rock were transported more than a mile to a level 600 feet higher and then dumped into Rattlesnake canyon. A million tons of wet earth had to be frozen by means of great icing tubes to prevent the mass slipping into the excavation area.

Work on Coulee Dam site began with core-drilling in the late summer of 1933. The starting of work on the dam project was hastened by the depression, when funds were allotted for public works to relieve unemployment. The Mason-Walsh-Atkinson-Kerr Company, holding the first contract, began work in October 1934; the first unit was finished early in 1938. The foundation, or so-called “lower dam,” was then in place. The MWAK company joined with other bidders in a new contract to continue construction, forming the Consolidated Builders, Incorporated.

On May 21, 1939, a bucket of concrete was poured which marked the completion of 60 percent of the 10,500,000 cubic yards necessary to complete the dam proper. The dam had already surpassed in size any other man-made construction on the face of the earth. On March 22, 1941, the first generators began to produce Grand Coulee power.

Farmers who located in the reclaimed area bought at prices ranging from $5 to $15 per acre land, which was estimated to be two and one-half times as productive as the average soil. At the time they were be required to pay, over a period of 40 years, without interest, the sum of $88 per acre for water rights, plus $3.19 per acre maintenance charges. Their houses were lighted and heated by cheap electricity.


1934 view of the Columbia River at Grand Coulee, before construction of Grand Coulee dam.

Source: Washington State Historical Society

Taken in circa 1940 by Bert W. Huntoon, this image shows Grand Coulee Dam.

Source: Washington State Digital Archives

1947 “Grand Coulee Dam, Eighth Wonder of the World” brochure – cover.

Source: Washington State Historical Society

1935 view of the Grand Coulee Bridge under construction.

Source: Washington Digital Archives


Grand Coulee Dam and is role in developing Washington State’s agriculture. Footage courtesy of the Washington State Archives.

Points of Interest Points of Interest icon

Douglas Park

Douglas Park is a publicly owned park encompassing 29.517 square feet located immediately downstream from Grand Coulee Dam. Douglas Park was built by the Civilian Conservation Corps in 1936–1938 under the authority of the Bureau of Reclamation, the federal agency that was in charge of building Grand Coulee Dam. The park, along with many other facilities, was built to accommodate and be used by federal and contractor employees working on the Grand Coulee Dam. Massive granite boulders and rocks blasted from the site of the dam were used to form walls, stairs, seating, viewing areas, walkways, and flowerbeds. The park’s location and use of granite rocks and boulders not only ties it to the history of the construction Grand Coulee Dam, but also lends to its natural beauty.

Grand Coulee Bridge

In late 1934, the Bureau of Reclamation began the construction of a 950-foot cantilever steel truss bridge across the Columbia River near the site of the Grand Coulee Dam. The bridge was dual purpose: it would transport heavy equipment across the Columbia during the construction of the dam, and after the dam’s completion, it would be used as a permanent highway structure on State Route 155. Approximately 300 tons of structural steel were used, which is supported by monolithic concrete piers that are 150 feet high and resting on bedrock. The Grand Coulee Bridge’s straightforward Warren truss suspended span and the minimal bracing over the piers reflects the refinement and progressive simplification of the cantilever truss form in the 20th century.

Grand Coulee Dam Visitor Center

Previously called the United States Government West Conservation Point and supervised by the United States Bureau of Reclamation. The center affords a splendid view of the slowly rising dam. During the summer months, the visitor center also produces a free, nightly laser light show off the waters of the open dam

Administration Building

The gleaming white Administration Building, once headquarters for Government construction engineers, is in the background. This is now primarily used as a police station. Directly opposite the Administration building, dorms for the engineers and nurses have been well maintained—the nurse’s dorm building is still owned by the hospital and used for storage, while the engineers’ dorm has been sold and is being remodeled as a bed and breakfast.