Washington at one time had it share of exceptional large kings!
Reportly the hatchery on the Elwha has collected brood stock that were as large as 100# - though haven't heard of any close to that large in several decades.
As mentioned the Columbia summer fish were hogs as well - remember reading some reports about the fish trapped when Grand Coulee shut off the upper river with fish in excess of 90 pounds being captured.
The Skagit in Puget Sound also had some very large fish. As recently as 25 years ago several fish in the 80+# range were reported. About the same time I found a spawned out male carcass that was about 66 inches long and wider than my shoulders - guessed its weight at ~75# - scary to think what it may have weighted in its prime.
While habitat problems (example the Columbia dams) have affected these giants the major problem has been the ocean fisheries. Fishing on these fish's feeding grounds (Canadian waters, SE Alaska, Washington Coast, Neah Bay) severely selects against these old fish (6 to 8 years old). While at one time it was commerical troll fisheries that accounted for much of the impacts now sport fisheries are a major source of impacts on these stocks and selection against old/large fish.
Tight lines
S malma