Grand Coulee Bridge by two concrete piers, about 150 ft high. During construction, one of the piers began to tilt, probably due to fine glacial material under the gravel. Additional supports were added as a temporary measure. The piers were later taken down to the bedrock using pneumatic caissons. Grand Coulee Bridge The Grand Coulee Bridge, or Columbia River Bridge at Grand Coulee Dam, is a steel thru cantilever truss bridge built in 1934-1935. It carries Washington State Route 155 across the Columbia River immediately below Grand Coulee Dam, near the city of Grand Coulee, Washington. It was added to the National Register
Grand Coulee Dam The dam's powerhouse began production around the time World War II began, and its electricity was vital to the war effort. The dam powered aluminum smelters in Longview and Vancouver, Washington, Boeing factories in Seattle and Vancouver, and Portland's shipyards. In 1943, its electricity was also used for plutonium production in Richland, Washington, at the Hanford Site, which was part of the top-secret Manhattan Project. The demand for power at that project was so great that in 1943, two generators originally intended for the Shasta Dam were installed at Grand Coulee to hurry the generator installation schedule. Water is pumped