On warm days I cannot resist heading to the mountain trout streams. I realize that the streams are so cold the trout will not be feeding aggressively and that I will have to dig them out with nymphs and Strymphs. When I developed the Murray's Strymph I saw it primarily as a smallmouth fly that would pass for a streamer to match minnows and a nymph to match the aquatic insects.
Several years ago when I made the DVD Fly Fishing for Trout, the producer asked me to include a section on fishing streamers in mountain trout streams. I seldom use streamers on mountain trout streams but in real cold water and very high streams I often use the Olive Strymph in size 10 with great success.
I fish the Strymph upstream and after it sinks deeply, I retrieve it back downstream using a 3 foot rod lifting and dropping bouncing motion every 5 seconds. The strike usually comes just when I begin lifting the Strymph.