The Dalles, Oregon, Wasco County
The Dalles is the largest city and county seat of Wasco County, Oregon, United States. The name of the city comes from the French word dalle (meaning either "sluice" or "flagstone" and referring to the columnar basalt rocks carved by the river, what the French-Canadian employees of the North West Company called the now-inundated rapids of the Columbia River between the present-day city and Celilo Falls.