The last data I remember reading on this topic was that in the large southern rivers the genetic makeup of the naturally producing wild fish is generally identical to the hatchery fish. Because the hatcheries on the Puyallup and Nisqually are the large production facilities the rivers have become places where the hatchery offspring sustain the wild population. The exception to this is white river spring chinook which are distict. Their may be new data on these systems but I am not aware of it.