The Stimulator is one of the most adaptable dry flies ever tied. Yellow body imitates yellow sallies and golden stones; orange imitates salmonflies; tan imitates caddis. The palmered hackle along the body floats it through fast water; the elk-hair wing reads as a bug profile from underneath.
Sizes 8–14 for stoneflies and big caddis; 16–18 for smaller hatches. A standard searching pattern when nothing in particular is on the water.