Fished there last summer (Aug) and found that the evenings as the sun started to set very exciting. Didn't get too much action during the day - early morning and later evening were the times you wanted to be out on the water. The lake was pretty warm so conditions will likely be different for you.
Found the small bay at the west end of the lake very good. Used mostly Carey Specials on sinking line - cast, count to 10, a few retrieves, pause, repeat. There were splashes on the surface, but never got a take on the surface that didn't start deeper down. I'm pretty sure they were following the fly to the surface.
I also hooked a great fish in only a few feet of water right at the campground. I was paddling back to shore in the float tube just after the last of the sun disappeared. I was paralleling the shore in water only slightly deeper then my dangling feet. As I pulled in the last of my line (maybe 10 ft of line + 12 ft of leader), my feet were hitting bottom and I was getting ready to stand up, when all hell broke loose. I wasn't really paying attention and all of a sudden there is line zipping out and fish jumping (at least thats what it sounded like as it was pitch black expect for my headlamp and the lights from the trailers in the campground). Talk about ending an evening of fishing with a bang. I scrambled to get things back under control; let line out while keeping some tension; got the tube back into water where I could maneuver; with the light from my headlamp I watched as my 6wt rod doubled over; and finally after several minutes I was attempting to land a huge trout that kept slipping in and out of my net as he was longer then the net was deep. Well I'll tell you that was one trout that came back with me for bragging rights and morning breakfast.
Good luck and tight lines.