Well you'd have to be willing to travel about 2 - 2.5 hours, one way, to fish the Umpqua.
However there may be some closer options, for lake fishing. Emigrant Lake is about 40 minutes south of Medford. And to the east of Emigrant are Hyatt Reservoir, and the much larger Howard Prairie Lake. I'm not 100% sure, but I think they all hold bass.