Cognito Brands Salmonfly Graphic Fishing HoodieSalmonfly Graphic Hoodie Fly Fishing Apparel The salmonfly is the largest stonefly to hatch on most of the rivers in the west. The nymphs will float around in the water and on the rocks for three years before hatching. Then they climb up onto rocks and trees before starting their clumsy flights. I remember the first time I experienced this primordial bug I was fishing on the Colorado River at the pumphouse near Kremmling. I must admit that I freaked