The Fall River is fishing quite well, mostly form the influence of ODFW stocking trout in the usual places. The nicest part of the Fall River in my eyes is how many dry fly opportunities are around now with different hatches, plus terrestrials like Ants and Beetles. The Mosquitos have been a little rough there too, at the Falls and Tubes and Campground be prepared with repellent. 
PMD’s and Olive Caddis are the main hatches. A #16 Henryville or #16 Olive Elk Hair Caddis is a super good dry fly on the Fall now. For PMD’s Emergers and Cripples like Film Critics and Knock Down Duns. I have always loved the Harrops Captive Dun for lakes during the Callibaetis hatches and we added his pattern in PMD size and color to the FFP offerings. Try it anywhere PMD’s hatch. I had good success with it on my last 2 days on the Met too.
Nymph fishing is excellent. Eggs, Zebra’s with a Tungsten bead and a myriad of Euro Nymph and 2 Bit Hookers and Micro Mayflies. Small Olive Streamers are consistently one of the favorites for the FFP guides, but consider Black or Natural colored streamers there too.