Three Creeks Lake is fishing well, but you can’t yet drive all the way to the lake. So if you have a pontoon, kayak or tube and are willing to carry it over the last snow bank you’re in luck. 
I’ve heard that little black leeches are doing great. Other flies I’d recommend are Red and Black Chironomids (16-18), Callibaetis Nymphs, Damsel Nymphs, Beetles, Ants and Griffiths Gnats. 
DOn’t hesitate to try that griffiths gnat dry or WET. Running a wet griffiths gnat behind a leech on a dropper tag is often very good on this lake.