The Fall River is fishing quite well now and would be a top pick for the upcoming New Year week. There are BWO’s #18-20 and Black Midge #22-24 hatches and keep an eye on some stray bouncing Snow Sedges #12 (a smaller cousin of October Caddis), but most the day will consist of euro nymph tactics or fishing nymphs and small leeches and streamers with a strike indicator. The fish in the Fall River are as picky as any in Oregon on a hatch, and it seems to me they are more easily fooled with cripples and emergers and by using 6.5x or 7x tippet.
On the nymphs, a 6x fluorocarbon tippet is just right, and with a streamer you can get away with 5x fc, or sometimes even 4x fc with a bigger fly.
Slum Lord in Cream or Black, Mini Gulp (Olive with the orange legs) , Natural or White Sculpzilla Mini’s and Black Balanced Leeches are great flies to strip, indicator or tightline.
Like the Metolius, the Fall has a short area of closure to protect spawning fish too, and that is from the falls to the confluence of the Deschutes.
Access now to the headwaters, campground, hatchery and tubes is all good with a lack of significant snow so far this winter.