On the Metolius River, August is always a good month for me, because it’s the month the summer doldrums that plague us a bit in July finally end. And the best is still coming. 
Now we are seeing good Golden Stone and Yellow Sally dry fly fishing in the Upper River from the Headwaters area to Gorge Campground. 
The entire river is seeing good #16 PMD hatches, #16 Tan Caddis, #16-18Little Olive Stones, some #20 Blue Wing Olives and the beginnings of an explosion of Yellowish Micro Caddis #18-20 in the Middle River. Any of these hatches could occur at any time of the day from about 11 AM to Dusk, and at Dusk you’ll want a good Rusty Spinner pattern tied on your tippet if you want to add a fish to the end of the day total. 
We’ve had a lot of really good nymphing action, mostly with Perdigons, Frenchies, Walts, 2 Bit Hookers, Caddis Pupa (Fat Ass Caddis), 20 Inchers (Green Drake Nymphs for prematch bugs that are getting restless) Soft Hackle PT and Micro Mayfly to meet the needs of BWO and PMD pre hatch drift. Add some Zebra Midges to the box and fish them deep and some Stonefly Nymphs, usually I would say Goldens about 90% of the time, but with the Cascade Stone hatch coming up in a few weeks also roll some large black stonefly nymphs under an indicator. 
There are plenty of big Bull Trout around now and we’ve seen some good catch rates, using mostly big steamers like the Milk Shake (it brings all the Bulls to the yard) and all Black Articulated, Black and Purple and Olive and White. Rolling them along dead drift under a big strike indicator is a good bet, and swinging them is also a great method. Give some of your presentations a strip across the currents too. Also some of the bigger Euro Jig Streamers like a Sir Sticks A Lot is quite good for Bulls.