Rich:
I dont want to talk about all of my ancient family trade secrets here, but you're on the right track.
I suppose if you'd email me I could share some of the formula with you, for exchanged info about holes / drifts up there...
The good Doctor Kageyama has some good theories in his book "What fish see" regarding fish's physiology as the migrate up river from salt to fresh. There's a good reason why you'll catch ocean-fresh fish on blues & greens, and older fish on reds & oranges, according to him. Then there's the water color light shift issue.
It's pretty complicated and all this thinking is making my head hurt. Later.