I enjoy using caddis patterns not only for the trout but also for the smallmouth bass on the Shenandoah River. An excellent tactic is to fish a pupa on a 5X dropper below the dry. In mountain streams in the East I usually drop the pupa about a foot below the dry. In the Rockies, if you are floating large rivers like the Yellowstone, it would be good to put the pupa on a 3ft 3X mono below the dry. The heaviest hatches on most mountain trout streams in the East take place the last two hours of the day. Usually I don’t see this hatch until April but it is early this year. I have already had customers catching some nice brookies with these flies in mid-March.
For the last several years we have come to realize the bass feed heavily on large nymphs. An effective technique is to wade into the river right below the heavy riffles and cast a Murray’s Bass Caddis Nymph across stream. After it sinks, swim it slowly across the stream bottom stripping it 6 inches every 4 seconds.