Only one guide on the entire San Juan that can outfish all other guides.. Andy Kim.
I've used him twice and his clients are catching so much more fish than anyone else on the river.. including the other guides. I've watched him as a client and at a distance the following days.. he is always catching fish!.. and mostly on size 22 and 24 hooks.
He is pretty arrogant overall, very specific on mending to get the fly down to the fish, and his teaching methods can rub you the wrong way, but he knows his stuff. His entemology knowledge puts him several notches above anyone else guiding there... that's why most all other guides don't like him there.
He is THAT good.