Kettle Falls was an ancient and important salmon fishing site on the upper reaches of the Columbia River, in what is today the U.S. state of Washington, near the Canada–US border. The falls consisted of a series of rapids and cascades where the river passed through quartzite rocks deposited by prehistoric floods on a substrate of Columbia River basalt. The river dropped nearly 50 feet (15 m), and the sound of the falls could be heard for miles away. Kettle Falls was inundated in 1940, as the waters of the reservoir Lake Roosevelt rose behind Grand Coulee Dam, permanently flooding the site.