There's reason to believe that so-called Chehalis natural Chinook production was an artifact of the Satsop hatchery and not so good natural reproduction throughout the rest of the basin. If so, that's gonna' be important to know.

Not bad SG as a quick down and dirty explanation. East Fork Satsop fish both Coho and Chinook went all over the basin. Records show many millions of Chinook eggs transferred to the old upper Chehalis hatchery and this went on for years. At the time HS took over hatcheries you could barely find a Chinook in the EFS. Chuck transferred the entire Humptulips production over a few years and genetically it was a Willapa / Hump cross. In its natural state the Satsop basin was a late timed Coho and early timed Chinook ( summers ). Run compression on Coho with millions of fry plants a year and commercial netting, including tribal, pretty much did things a flip all over the basin.

The simple fact is despite it being the 2nd largest watershed in the state the Chehalis was primarily a Coho steam with very distinct Chinook populations scattered trough the tribs, in the natural past. When you manage things as a whole with little regard to the population break down then you get what we have. Chinook productivity in the best of times was nothing compared with many streams and the harvest rate applied both past and present in the ocean intercept fisheries will not allow much of a terminal fishery. Any available will get taken with the tribal / commercial nets and sport C&R mortality.

Fact of life.