Bass are not native to our lakes and were not introduced by MNR. Many of these larger, deeper lakes were natural Lake Trout lakes. They are now mostly gone with the odd one reported caught. Surface Temp (ST) was 72F even early in the AM. That is getting close to fatal temperature for Rainbows (75F). By noon we both had caught one small Rainbow each. At about noon I got a 4# Rainbow on a Green Slumpbuster (close to a Zuddler, only with rabbit strip around the collar) on a #4 sink. I had a white BH WB as the dropper and attractor. I often do that on these clear lakes. There aren't that many fish per acre and you have to do something to get them over to have a look. Pretty good fight, few jumps and a few runs. I was about to take a picture of it while holding it by the hook in the water and off it went, no worse for wear. I try not to even use the net, certainly don't take the fish out of water.
One other bump was the only other action, other than the occasional cast to shore to bug the bass. If you get a bump/bump, that is a fish hitting your fly with its body and then its tail to see if your fly is something that even resembles food.
And then I noticed the water temp: 74.2F !! and headed back to the launch with a few casts along the way. I caught this guy. Didn't jump as high though. Notice the rough looking tail and stabilizer fin. This guy has seen some action.