Clarkston is a city in Asotin County, Washington, United States. It is part of the Lewiston, ID-WA metropolitan area, and is located west of Lewiston, Idaho, across the Snake River. The population of Clarkston was 7,229 in 2010 census.Walla Walla Community College opened a branch campus in Clarkston that serves the surrounding area. Clarkston's ZIP code, 99403, is the highest in the contiguous United States.

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