I've never fished for them south of the Canadian border but would love to try. What fly were you throwing? My best success on the fly has been a big bob's banger like the one pictured. I throw it almost always and almost always get at least a follow. I fish them from calm sunny days to rainy windy days on unfished portage lakes and big lakes that get pounded with Mepps on baitcasters. They almost always produce. I would love to have the chance to chase Musky down south but my limited fishing time usually takes me to the mountains. My only advice is to keep going after them and fish a fly in the 6"-8" range that moves water, whether that top water or subsurface.