Q: How do you fish for large trout laying in deep runs 8+ ft? How do you rig for them? What about sinking leaders on the narrow streams with these deep holes/slots holding fish?
A: There are several techniques used to approach trout holding in this situation. The first thing I would do is try to observe how they are feeding if at all. If they are chasing other fish around or nipping at their tails my first choice would be a streamer. Something with some weight (i.e. Wooly Booger, Slump Buster, Meat Whistle, Double Bunny) A sink leader would help out in this situation by getting the streamer to the bottom quickly. I would start out by presenting the streamer with little to no movement. Almost a dead drift if you will. I try to keep just the out that is needed. Slack line will prohibit you being able to detect the strikes. I would gradually increase the amount of movement by increasing the amount of line brought in with each strip of the fly line. If these techniques did not work with the streamer and the fish is still chasing others I would try to hang the streamer right in the fishes face. This makes the larger fish think the streamer is moving in to compete for food. The larger fish will usually run out the other fish if not devour it.
If the fish is not doing a lot of movement but you can tell he is feeding (seeing the white of the mouth) I would approach using a double nymph setup. I would set my leader up to slightly deeper than the water and tie on a smaller soft hackle Pheasant Tail size 16-20. I would then drop a heavier Stonefly at the bottom of it. Although I highly recommend fishing with indicators, water of this depth sometimes demands an alternate solution. We use the fly line itself as the indicator. Try to keep just the tip of your fly line on the water to get as slow a drift as possible. If a fish strikes, the tip of your fly line will jump similar to the way the indicator moves. Start by dead drifting the nymphs, but then add a slight (2-3in) lift numerous times through out the drift. This resembles some of the pre-hatch movements of nymphs, and can be the deciding factor in making trout eat. In both techniques I will add weight 3in ahead of the streamer, or the bottom fly to begin with. I will then add more weight slightly up the leader if I feel I am not getting down deep enough. If that is not enough I will add weight to the top of my leader. I personally do not like to fish sink tip leaders on smaller streams. Although there are holes/pools that it could help out on, they make up such a small percentage of the stream.
~ Josh Garris CWO Professional Guide