I saw the same thing except on a river in downtown woodinville. In Woodin Creek which is at the largest about a foot across and 6 inches deep, on the bank i found a dead 8-10 maybe 12 lb hatchery king. Definetly no hatchery on that river. Woodin Creek does empty out into the slough. Are there any hatcherys on rivers that flow into the slough?.... FisherMan8989