It's worth it to wet a line.
There won't be too many people swimming in mid DEC.
North on 89 anywhere past the Dariy Queen is pretty good.
Don't lug out lots of stuff. You can get by with a short rod since there is lots of growth.
Bring a box with some black and brown wooly buggers, a couple of BWO patterns, some spinner patterns or general dead-mayfly-floater things, and some standard nymphs like pheasant tail, hares ear and some kind of small black split tail nymph.
Waders help a little but there is adequate access streamside.

I will give away no more secrets!!!!!!

Best of luck to ya