While not wanting to be totally defensive of the current regs, as they are rather messy, there is one overriding reason for the complexity and that is to provide opportunity. Given ESA listed stocks and species and/or a weak return on a non-listed stock (eg GH salmon that have missed escarpment for how many years) the simplest reg is CLOSED for the watershed. Makes for a small pamphlet.

You have areas above barriers with only resident fish? If there are no native char, this could be opened. But, you will have to list above each barrier.

Maybe you have a hatchery in the system. Downstream of the hatchery you could open for hatchery fish, if the wild fish could take the release mortality.

And so on. The regs are complex to (generally) squeeze out the most opportunity. On something like the Hoh, with parts in ONP, they may apply their rules.

Again, not say that WDFW doesn't need to clearly and transparently explain why there are such complexities but (at least in the past) complexity was so that folks could do some fishing.