Fair Hooker -
You are correct in that there is a growing body of information indicating that hatchery fish (regardless of brood source) spawning with wild fish results in lost of productive. However don't think that is the answer to the questions that I posed.

1) The Keogh River on the NE end of Vancouver Island is a site on long term studies. The fishery is CNR, no hatchery fish (just recently started a wild brood program). Escapements of wild steelhead fell from more than 1,000 in the mid 1980s to less than 100 in the mid to late 1990s (before brood program).

2) Both the Cedar and Nisqaully have not been planted with hatchery fish (Cedar a limited number of wild brood stock) in a decadde or more.

3) North Fork Stillaguamish and Snohomish case - In the 1980s the hatchery fish spawned well into March (possibly into early April). It has been estimated that the over lap between hatchery and wild spawning steelhead at that time was 10 to 15% (10 to 15% of the wild fish were spawning at the same time and place as the hatchery fish) yet a spawning escapement of say 6,000 to 7,000 fish would produce runs of 8,000 or more fish. By the late 1990s the hatchery spawning had been altered so that virtually no fish spawn in March. The over lap in hatchery and wild steelhead spawning has been reduced to less than 1% yet recent escapements of 6,000 to 7,000 have produced runs of only 3,000.

Regarding you randomly generated S/R curve - not sure that 69% harvest rate is the same as 40%.

Tight lines
Smalma