Deschutes River / June and July
I fished 6 days on the Oregon Deschutes so far this summer; June 7-9, and July 19-21. I hope to go back in September or October.
The June trip was late in the salmon fly hatch, but there were still quite a number salmon flies and golden stones about, and the fish were looking up. We did 3 day trips in my drift boat from Warm Springs to Trout Creek, about 9 miles. Good long days on the river. Some coolish weather and we caught a bit of rain, but we were fine in waist-high waders. My midwest friend and I got into a number of good fish on a couple of different dry patterns: the chubby chernobyl with light orange (salmon fly) or pale yellow (golden) underbody, and the Henry's Fork stone. Great fun to have a fat 16" redside charge out of the water to attack your fly. I also had some success indicator fishing the nymph, typically #14-16 flashback PT on point with a smaller sparkle pupa or hare's ear dropper. Did not fish stone fly nymphs but they can be very effective in the right places. We saw some PMDs on the water but the fish did not seem to be interested. We hoped to see green drakes in the evenings, but did not.
The July trip was with my main fishing buddy - my brother. We also did 3 day trips from Warm Springs to Trout Creek. Days got quite warm, highs in the upper 90s to maybe 101-102 on the hottest day. Good days to wade wet. Caddis were abundant and we found rising fish in some very focused areas. The winning dry fly was a #18 tan elk hair caddis or x-caddis. Nymphing again was successful with similar setup as above. My brother caught the largest rainbow I have personally seen on the Deschutes, a thick-shouldered 20" brute. We caught several in the 16-18" range as well.
We fished the dry flies with 9'5wt rods and 5x tippet, though you can sometimes use 4x. Fish are not particularly leader shy in the current seams, but can be selective in slower waters where they have time to really look carefully (and we did observe this). We nymphed with 9'6wt rods, 4x tippets.
Fishing from a floating device is not allowed on the Deschutes, so you do not typically catch large numbers of fish: 6-8 fish each would be a good day. But the fish you catch tend to really strong fighters and are beautifully colored. It's a bit demanding getting in and out of the boat in awkward locations a dozen or more time a day (you seldom land on a beach or a calm shallows), perhaps scrambling up a bank to get to a particular run or feeding fish, and wading knee to upper thigh deep in current with slippery rocks underfoot. So it's not necessarily an easy river to fish when you're a little older, but it's one I really enjoy.
The river itself is easy enough between Warm Springs and Trout Creek, all Class I water. It has a strong current though, and there are a few rocks, small standing waves, and other obstacles to negotiate. Below Trout Creek there are several significant rapids, most notably Whitehorse Rapids, a long and rocky Class IV that takes experienced maneuvering.
Happy to answer any questions..

As a resource, my steelheader son has floated the lower DesChutes about 20 years in a row, but for steelhead, for what it's worth