This business of "on again/off again" flows on the Elk are not helping the fly fishing. We get the same kind of problem on the White and Norfork Rivers in AR when they practice the same kind of "up and down" levels. The fish seem to like some degree of "consistency" in water level/flows, and when they don't get it, they sulk. The only variation that I know of is in fishing the really deep holes where the fish don't seem to notice the "ups and downs" as much.