There are 4 US Post Offices in Skamania County serving a total of 7,757 residents equating to 1,939 residents per post office. It's estimated that approximately 12,381 packages are handled across the 4 county post offices annually. Skamania County /sk\u0259\u02c8me\u026ani\u0259/ is a county located in the U.S. state of Washington. As of the 2010 census, the population was 11,066. The county seat and largest incorporated city is Stevenson, although the Carson River Valley CDP is more populous. The county was founded in 1854 and derives its name from the Cascades Chinook word sk'm\u00e1niak, meaning \"swift waters\". Skamania County is included in the Portland-Vancouver-Hillsboro, OR-WA Metropolitan Statistical Area."