Todd -
In at least the case of North Puget sound rivers I don't think one can lay the blame of the demise of the early wild steelhead on the Chambers Creek steelhead. An interest read is Enos Bradner"s Northwest Angling published in 1950. In that book there is a chapter where he discusses the steelhead rivers of Washington. As part of that discussion there are description of the best times of to fish various rivers. That information comes from his and other anglers experiences on those rivers as well as the steelhead punch card summaries from the 1940s. Remember wide spread success with the early timed Chambers Creek steelhead was not achieved until the early to mid-1950s.

A couple examples -
Skagit river - "... It is fished very little during December, but January is good, and the period from Washington's birthday until the end of March is the best".

That sounds much like we see today.

The Skykomish -
"Its best months are January and February. Some years there is a late run in March after the season closes."

It looking at the early sport catch records keep in mind that the general winter steelhead for most rivers was December 1 through the end of February. On some of the larger rivers portions of some of them were left open later (in some cases even in to April). It should not be a surprise to anyone that the majority of the recorded steelhead change in the December to February period far out numbered the catches in March and April. Not a function of run timing but when folks could legally fish.

The snow fed rivers of north Puget Sound have an extended run-off period that last well into the summer (in the case of the Skagit until early August). This selects for a late spawning population (young fry emerging from the gravel during the peak of that run-off would have diminished survivals. While the major of those basin have hydrographs drive by snow run off as Salmo g suggest some the lower basin/low elevation tributaries would have had hydrographs that would have been more suited to an earlier timed and earlier spawning population. But those basins were trashed more than a century ago. In most cases with nearby late spawning populations in the main stem and the typical inter play between man stem and tributary spawning the few fish found in those tribs can be expected to be largely populated today by those later spawning fish.

The situation with those north Sound Rivers is very different than those on the Olympic Peninsula where the rivers with declining hydrographs occurring much earlier in the year early returning wild fish were commonly found.

curt