Big Hole River 415 cfs
Beaverhead River 472 cfs
Adam pretty much hit it on the head on his comment describing a toilet flusher.
There are sippers, super sippers, splashers and toilet flushers.
Now the super sippers are quite deceiving and at times not even noticeable except to the trained eye. Many times I have told my fisherman to set it and they look back at me like I was nuts and say they didn’t see a thing and the fly just sunk on it’s own.
These super sippers are a times very large fish. What happens is the fly just disappears as this big fish does not waste much energy taking this little fly and he basically inhales it.
The sippers and splashers are pretty easy to see.
Then there is the toilet flusher. I have had people almost jump out of the boat when this happens. It normally happens with large flies, salmon flies, hoppers, chernobles etc. A big fish sees this tender morsil floating by and he is not going to take a chance on missing it or letting one his buddy’s get it first.