Construction of The Dalles Dam formed Lake Celilo, flooding the major Native American fishing site of Celilo Falls, in 1957. The Dalles Dam is a hydroelectric dam spanning the Columbia River, two miles east of the city of The Dalles, Oregon. It joins Wasco County, Oregon with Klickitat County, Washington, 192 miles (309 km) upriver from the mouth of the Columbia near Astoria, Oregon.