The highest I have really fished it is at 4500 cfs, but it had been falling at that point and while not clear was fishable. Had it been rising to that I've no doubts it would have been muddy. I generally like the flow from 2000 to 3500 cfs, and can figure at that flow rate the water will be in good shape. Watch the flows for a week or so before you go and it will give you a pretty good indication of what the water will be like.