Lead thrower -
Bob is correct! The standard Puget Sound hatchery steelhead are of 2 general stocks. The winters from a composite early stock called Chamber's Creek (a hatchery located in south Tacoma on a creek by that name) and the summers while now from the Reiter (South Fork Skykomish) were originally form the Columbia country - Skamania stock.

The physcial characteristics of fish are the results of selective pressure on the population for what works best for the fish. What genetic traits that allow for the best survival are passed on to the next generation at higher rates than those traits that are less advantageous.

That can mean that fish can be very different in different environments. Not all wild steelhead are large fish. For example nearly all of the native summer populations of Puget Sound are almost exclusively 1-salt fish (less than a 5# average)- the Deer Creek fish (North Fork Stillaguamish) are more than 95% 1-salts. While some of the winter populations from the same river systems are more than 50% 3-salts. The reason of ocurse is that 1-salt size fish are more successfully accessing and surviving in their headwater streams. The larger size associated with 3-salts works best in the large rivers with their larger substrates.

Bob mentioned the large kings found on the Kenai. Many have forgotten that similar sized kings were once found here right in Washington - examples include those found in the Skagit and Elwha. Those brutes of more than 80 pounds (in the case of Elwha some exceeded 100#) are older than the "normal" chinook perhaps as much as 8 years old. We lost those monster fish because being large long lived individuals was not longer a successful strategy. Those old fish were selected against by our fisheries (sport and troll) on their feeding grounds. The longer they remianed at sea the higher the probability that they would be caught - a fish returning after say 2 years of being fishing on have higher survival rates than those being fished for 4 or 5 years. If we wish to see those fish again that we to insure that being long lived is an advantage.

Tight lines
Smalma