Watching or hearing a trout hammer a mouse pattern on the surface is not only one of the most explosive thrills in flyfishing, but it will also change your perception of salmonids. Gentle sips? Soft takes? Not here. When browns and rainbows reach a certain size, they cannot survive by eating tiny insects exclusively. Trophy trout require gobs of protein to maintain weight, so they turn to baitfish and scads of unfortunate mice that fall into the flow. Any river in the country that holds trout is worth mousing. In the East, this game largely revolves around fishing in the dark when elusive giants get on the feed. In the West, however, guides have learned that there is a time and place for mice while the sun is still shining. I live in Colorado, and that’s my camp. Joe Cermele, on the other hand, is a Northeast native, who is tuned into the dark side. We’ve talked to some of the best mousers in the country. Pick your poison—or mix their tactics to make your own mousy cocktail—and call up a bruiser on your home waters this summer. —K.D.