I had good luck at Chelan my first time out.
I recommend Rick Graybill's book on Fishing Lake Chelan. We caught 3 small lake trout near the "narrows" using a hot spot flasher and herring in a "crippled anchovy" bait holder. We caught them deep; over 300 feet on bottom.
You must add longer downrigger cables, 400 or 600 feet long. Electric downriggers are required; unless you're an idiot. Good luck.