Don't forget the Washington side of the Columbia River. A couple of parks come to mind: Maryhill State Park (
http://www.parks.wa.gov/parkpage.asp...yhill&pageno=1) and Columbia Hills State Park (
http://www.parks.wa.gov/parkpage.asp...ills&pageno=1). I have camped at Maryhill - interesting area. A full scale model of Stonehenge and the Maryhill Museum of Art (
http://www.maryhillmuseum.org/) are close by. Up river from Maryhill on the Washington side (Hwy 14 - two lane, but it's a good road) there are several great wineries to visit.