Grand Coulee Bridge 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 of Historic Places in 1982. The bridge was built to transport heavy equipment across the Columbia river during the construction of the dam, and thereafter as permanent highway bridge. As such, it was designed to carry a heavier load than was typical. The bridge is supported
Grand Coulee pumped from the Grand Coulee Dam, into Banks Lake to act as an Equalizing Reservoir and irrigation water source. Evidence of the waterfalls includes a plunge basin where the falls began, immediately south of Coulee City. It contains at least of gravel lower than the open flooring of the land. The river above the falls was shallow and much wider than the gorge. Thus, it wrapped around the lip of the main falls creating lateral falls. These flowed until the recession of the main falls denied them water. Northrup Canyon in Steamboat Rock State Park, contains a dry cataract as