Anyone who wants more info can PM me. But you got it sorta. The hatchery stray rate was huge for years as they ran by ( many ) so good bad indifferent the hatchery coho & wild are same genetics. The feds bitching is why the coho releases were steadily cut back for years. The Chinook the same but they went to native broodstock and reduced the impacts but only to a degree.

The solution is a Stevens Creek intake and pipeline to give a non river water source to attract. ( Hump is pumped river / mostly ) Paul Seidel tried his best, as did Jim Scott but the lack of a all out push from locals let it get axed.

The long and short of it without the hatchery production supplementing the wild spawning populations there ain't no way the Hump productivity is high enough to support the tribal / sport / commercial fisheries as they exist. The fear we faced then and now was the Coho could be driven down enough to lock out non tribal harvest on Coho. Chinook are the great unknown but everyone needs to come to grips with the fact that that tribal harvest comes before ANYTHING including conservation.

Bone tired from three days non stop fishing so forgive typos.

edit: As to habitat. Look at the timber age group and past / present / future harvest as tree farms are on 40 year rotations. The Hump habitat is in decline to a degree and will plateau out someplace just as the Chehalis ( and tribs ) has. That productivity will be less than past & best hope is stay at the present level. To see improvement? I doubt it as I worked for 38 years in the woods and have seen, and in my job contributed to, the accumulative impacts of tree farms which are huge and agencies have no way to adjust to it.