The smell of balsam fir floats through the air as you squint to tie on a fly in the fading light. As you ease your way into the river, a trout dimples the surface tempting you to shoot off a quick cast. No. You wait to compose yourself. Calm your nerves and make it count. As you have learned many times before, you might only get one chance. Finally with a steady hand and a slow deep breath, you sail your fly line through the air and across the river to perhaps the trout of a lifetime. Your drift is good. Your fly sits high on the water, naturally drifting toward the feeding fish. Pause. Wait. Be ready.