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. Also in the same area was the Petite Dalles or Little Dalles, or Short Narrows, which is now also inundated. The site of what is now the city of The Dalles was a major Native American trading center for at least 10,000 years. The general area is one of the continent's most significant archaeological regions.