Resident chinook in lake Sammammish? Now that would be something. I guess it could be possible since it worked in lake Chelan. Seems you would hear of more being caught. Too big for a smolt, I stand by cutthroat.
BTW, I confronted a few of those "jig fishermen" a couple years ago. They were practising "horizontal jigging". Kinda ugly as you would expect. When the park ranger showed up they were all gone...