I wonder what environmental conditions caused a few select populations to favor fish that were 6 and 7 years old (and hence huge)? The "June Hogs" in the Columbia traveled a very long way to their spawning grounds, over some pretty heavy whitewater, so maybe it was only the biggest and strongest that could survive there, but as for the Kenai and the Wannock? Neither of these rivers are long (the Wannock is short). Is it a lack of predation that caused bigger fish to be favored there? It is a shame that the giant Columbia fish were lost forever when Grand Coulee dam was built.