The nymphs leave their burrows after sundown and about an hour before dark. Their very quick move to the water surface, casting the shuck and flying off leaves small opportunity for nymph and emerger fishing. When trout detect this hatch, they take up stations in the current in preparation for the spinner fall which occurs within the hour. While a few fish may be taken at this time, the real action doesn't start until the spinners start to drop at dusk or after dark. At this time the water is covered with spinners and the trout eat ravonously but very selectively. The fisher must determine the size and which posture of the natural they are feeding on; dun, semi-spent or fully spent. Pick out a couple of feeding fish and concentrate your casts there. Try to determine the rise pattern and time your cast accordingly.