I am going to Montana next weekend to begin a new therapy for Parkinsons that is available in Louisville, Ky as the closest point to Knoxville. I have relatives in Great Falls that I will be staying with while I do the month long therapy (4 days a week). I am going to take as much advantage of this opportunity as I can to flyfish as possible , but will be limited somewhat with transportation , etc..... Does anyone have any knowledge of the following streams as to good fishing areas , wading access, etc......

Big Spring Creek - Lewistown, Mt
Wolf Creek - North of Helena
Sun river - west of Great Falls
Thanks for any and all help
Mike