The Lower Deschutes has fully transitioned to Summer Hatch Mode! Caddis, Pale Morning Duns and Pale Evening Duns are the main hatches and will be the mix nearly every day for the next month or more. 
The Pale Morning Duns are #16 and have 3 tails and the Pale Evening Duns are #12 or #14 and have 2 tails and Blueish eyes. Both are gorgeous mayflies and can be matched with a Yellow parachute, Comparadun or Sparkle Dun but choose your hook size carefully. A Purple Haze and Parachute Adams are good dries for the mayflies too. And Rusty Spinners will be something to watch for in the eddies in the afternoon and in the softer water in the evenings. 
On the caddis hatch I think there is no better fly than an X Caddis on the D. It is a solid emerging profile. The Iris Caddis is a low floater but it really shows up on the water well for us with older eyes because of the white loop of Z Lon on top. 
You’ll also want an Elk Hair Caddis and Corn Fed Caddis for the adults in a #14 and 16 and keep an eye on the Little Western Weedy Water Sedges, which is a #18 Black Caddis that hatches near the edges off the willowy weed beds. 
The nymph fishing is outstanding of course (in the right place at the right time which is the story of fish). Perdigons, Frenchies, Copper Johns, PT’s, Caddis Pupa, Walts, 2 Bits in BWO and PMD size and color options and Mini Gulps and other Micro Streamers to match Sculpins, Crayfish and Minnows.