I’ve been in Chile for the last 12 days so I am getting updates from friends and family on how fishing has been in the area, and it seems like the Metolius is by far the best option of any of the local rivers right now. There are afternoon hatch of BWO’s, quite a few Silver Stripe Sedges and Midges. Whether the fish come up to feed or not depends on the day and location and a little lady luck, but you should be able to get them on nymphs most days.
Bull Trout fishing is still active, it seems like the bigger fish have gone back to the lake leaving the resident fish to do battle with now. Nothing wrong with that! Streamers are good, although if you want to try another way I always like a #10 or #12 Red Ice Cream Cone (like you use at Crane Prairie in the Summer) under an indicator. Probably best to get there early, but with these darker days in the forecast I doubt it makes much difference. I think rainy days are great for catching BT’s on the Metolius.