I was at upper K about a week ago and I seen a school of about 20-25 bulltrout swim by(no kidding). They were about 300 feet to the left (south) of the boat launch. They couldn't have been more than 10-20 feet from the shore. You can only see them when the water is calm typically but if you can hit it between 10 am and 1 you will probably have some luck seeing them. As i'm not an experienced bull trout catcher I couldnt land one. I danced a few clousser minnows in front of them and nothing. A guy at whole sale sports said to me maybe I should dangle a cut throat in front of them...he's right...lol.
Honestly though man I would try a really really large streamer in there as they are the top of the food chain in that lake.
Good luck to ya friend.