Re: Madison Valley or Gallatin Valley help needed
Actually, a number of small streams coming into the Yellowstone in Paradise Valley hold plenty of fish once you hike up them into the mountains a ways and get above where they get diverted for irrigation. Pine Creek, Mill Creek, Six Mile Creek all have fish. But it's usually pretty tough fishing, with close quarters casting and a lot of rock scrambling. Not for the out-of-shape.
And by that time of year, the Yellowstone itself is low enough that it is surprisingly good wade fishing. Just pick an access that has a lot of gravel bars and islands in sight, or stretches where you can walk the edges below the high banks. Side channels around islands that still have running water often hold a lot of fish that haven't gotten pounded by the floaters. We used to have a cabin near Emigrant, and I'd park at what's known as the Wanigan on the East River Road where it swings in against the river and fish one wide, shallow riffle below a little island. I could spend several hours nymphing that riffle, and while I didn't always catch a bunch of trout, there must have been thousands of whitefish in that riffle.