25 years ago, 3 of us could each catch 10-12 whitefish in a few hours upstream from Taylor bridge, by Bower Ponds in the middle of July. We used teeny panther martin spinners or a fly bouncing along the bottom.
By Dickson Dam, there was a single day in September of about 10 whites in 3 hours, using a standard nymph fly fishing rig, It have been back twice, catching about 4 fish in 3 hours using the same techniques and flies.
So, either their tastes have changed, or they are not there. Or, it could just be luck. That is why I would like to try a fresh new spot.