Sandy and Clack have clipped silvers (coho). I think the Sandy has better luck, what with the infamous Clack River Lockjaw Coho strain.
Fall is much better on the other side of the Coast Range.
Not counting the Columbia, which has the biggest runs of any river anywhere (in the world). But it's tough to bank fish in the fall (or so they tell me, never done it, only plunked in spring). But there's people here who know much more about Big C plunking than I, so I'll defer to them.