I can think of a few rivers, though I am not sure how many, where the hatchery does not have a seperate channel but rather are stopped by a weir. Chambers creek, the Green off the Toutle, the Sooez (Neah Bay) are just a few. I suppose the barrier dam on the Cowlitz and the Dam on the Kalama would qualify, though I am not sure how many hatchery fish were stocked this high.
Many of the smaller, Hatchery creeks have weirs too, but these would not intercept as many. Without clipping, it would be impossible to tell the difference. Just seems like there is Death by a thousand cuts. With clipping, this could be easily eliminated, so it would not apply today, but it could be part of the demise, on top of harvest, that killed off the early run portion.