On the Metolius River, fishing is quite good and should stay that way until at least November, with the best fishing coming Mid August to Late October for me every year.
PMD #16 in all stages (nymph, emerger, cripple, dun and rusty spinners), BWO in all stages (#20-22), Pink Lady #16, Ameletus #14, Caddis galore #14-18 in Tan, Olive, Charcoal Black and Yellow, plus Golden Stone adults #10-12, & Yellow Sally #16-18 stoneflies. 
Keep an eye out for some Salmonflies this month and the by the end of the month we should see the huge Willowflies #4. Usually in Mid August a minor Salmonfly Hatch will extend throughout the river, sporadic and spread out as it can be, it can also provide smashing takes for a few days here and there as it jumps around the different segments of the river. 
Most of the Golden Stone hatch is still high up in the river, above the Gorge CG. Clarks Stones and Norm Woods Specials are the flies to match the goldens. 
All other hatches are pretty wide spread in most areas. 
Tightline/Euro nymphing has been excellent in all areas for trout, and several nice Bull Trout have also been fooled with a perdigon lately. Olive and Brown Perdigons, Jig Rainbow Warriors and Walts Worms have been hot flies. 
There are a lot of Bull Trout in the system. Get out early to have the best chance of catching a Bull. Do not forget the tributary streams are off limits to fishing. They are protected waters closed to all fishing so Bull Trout have a safe place to spawn and juvenile fish have a sanctuary to rear before going out to the big river to grow up and get mean!