Fall River (and the Metolius) are the best bets for Central Oregon at the moment, with the consistent temperatures of spring water not allowing the rivers to freeze up, and keeping the bugs and fish active.
We are seeing some BWO’s in the afternoon, especially around 1 or 2 PM, mixed with some small black midges throughout the day.
We’ve had incredible success with 6.5x and 7x fluorocarbon tippets with small, heavy nymphs and 2 tone squirmey wormies.