A little warning... in areas open to fly angling only, no additional weights or attractants shall be added to the line, leader or hook. Meaning no split shot on the leader when fishing above bridge 99 on the Metolius.
I haven't been up to the Metolius in years. The method I used in the past was fishig two flies on a floating or sink tip line, depending on water dpeth. The lower fly was a weighted nymph, often a stove pipe (grey, black and green striped with single feather) or dark wet caddis pattern, a dropper is attached above the lower fly. The dropper I used was small, like size 14 to 20, can't remember the pattern. This setup usually got some hits in the first few cast, after that, the fish seemed to get educated real quick.
Anyway, have a nice weekend Big Tuna, hope you find some willing fish.
Gregg