I like to be there the first week of October. No tourists and the trout fishing all to ourselves. Of course over say a 8 hr day of fishing, you might actually only get 4 hrs in the water with all those bears cruising around.
Must be awesome to be able to get out there when there are few tourists.
Looks like this is one place where the salmon fisherman hang out...I am not sure of the precise location, I am assuming near the park headquarters?
Lower River cam 
