Streams become unfishable when:
There is a flood
The season ends (10/31)
Or, when it becomes hard (ice)

Fall does tend to become more difficult as the insect hatches become less, and less. For this guy that is the time for Steelhead, lake run Browns and of course Salmon, which I don't know if you are aware there is an abundance on the western shore of Lake Michigan, and the southern shore of Superior, all within a 3-5 hour drive from McCoy.

Mike