Re: Madison Valley or Gallatin Valley help needed
Big creek may be too low to fish in Sept. But you could take a walk up Mill Creek. Little access but once you get in it can be really good.
If you are not afraid to drive, I would look at the Boulder south of Big Timber. Decent access and it is right up your alley. It is a little smaller than the Gallatin but same size fish. You might also consider the Shields. Both are outstanding wade fisheries.
Besides the Gallatin, you might also consider the East Gallatin. I think there are bigger fish in the East Gallatin but not sure how much that matters.
Sounds like you know which waters to target in the Park.
Let me know if you have any questions.