Not sure it would be worth the trip over there for one fish.Over the years there seems to be more and more of them.It is going to be an issue sooner or later that someone is going to have to deal with for sure.
You may want to watch the seasons and limits, often the lower river limit will be one chinook, then up river two chinook. I think there is an endangered tulie stock down low they are trying to protect. Most years, by early to mid-Sept, the chinook fishing further up is pretty good, you may want to visit with your guide about that.
Two seasons ago the Silver fishing was off the hook and as I recall opened to 3 Silvers in Sept. By mid Sept, silvers averaged 7-10 lbs, a few 3-4 pounders and several 15-18lb fish in most boat limits. We had great silver fishing into Nov that season, with legit 18-22lb hatchery silvers on occasion. That was a blast and worth a trip, limits were the norm.
A few years back the limit below Bonneville was 3 chinook, so it pays to watch it. Heck, last year they opened it for Chinook 7/1, with a specific boundary at Astoria, the fishing was quite good but limited to one chinook, no one was there. If you want to follow it, sign up for the email updates for the Columbia zone on the ODFW site, if you have not already. I'm pretty plugged in to the lower river fishery, so if you see a season change and want a report, just holler. I'll tell you what I know.