<Tr> <Th> Area code (s) </Th> <Td> 458 and 541 </Td> </Tr> <Tr> <Th> Website </Th> <Td> City of The Dalles </Td> </Tr> <P> The Dalles / ˈdælz / is the county seat and largest city of Wasco County, Oregon, United States . The population was 13,620 at the 2010 census, and is the largest city on the Oregon side along the Columbia River outside the Portland Metropolitan area . </P> <P> The site of what is now the city of The Dalles was a major Indian trading center for at least 10,000 years . The general area is one of the continent's most significant archaeological regions . Lewis and Clark camped near Mill Creek on October 25--27, 1805, and recorded the Indian name for the creek as Quenett . </P>

What is the population of the dalles oregon