They normally do it almost every time they get startled or to startle what ever is after them,but I think on some of the holes on the west branch its a learned response ,they learn that if they bug you enough you will leave.Most of the time though they are just trying to get past you.  Jim

Are you saying that he as doing it to scare people (me) off? Or was he slapping at fish, much as large fish might do with their tail to stun their prey.

When they release water like that it will bring a lot more green up from the bottom.  Jim

You guessed that right,the beaver thought that you had fished enough,and it was time for you to leave so it come out and gather some food,I've actually had them circle me in the spring and my brother had one chase him out of the water.  Jim

On Friday I intended to fish the Deposit area but when I got there the water quality, as you probably already know, sucked. The water was high, which was no problem, but for the first time this year it was brown and muddy. In addition, the water column was permeated top to bottom with spinach. Impossible to fish any kind of artificials without cleaning off after every cast and then stripping off any weeds that collected on line that laid in the water while you cleaned off your fly.

So I started the day at junction pool in Hancock and then spent the rest of it exploring the East Branch.

What was it about Friday's flow that caused the muddy conditions and why hasn't that happened earlier this year (Or has it?!) . As far as I know, there wasn't any rain the day before so what's up with that. I noticed that the CFS jumped from 600 to almost 1200 on Friday morning, so if I had to guess at it I'd say that the sheer volume of water they let loose stirred everything up but I don't know. Just curious.

I did manage a decent day with a nice size rainbow (roughly 18" caught on a black ant) and one nice brown (roughly 17" on a pheasant tail nymph) and a smaller one ( about 10" on a black woolly bugger at dusk). Also caught some sunnies at dusk on the black bugger too - big and fat!

Yesterday I fished the upper East Branch and while I was on the water at dusk I was startled by a humongous splash in the fog about 30 yards from me. It sounded exactly as though someone had dropped a cinder block from the air into the water. One LOUD splash and then silence. The tone of it was very deep, which is why I used the cinder block analogy. There had to be a lot of weight behind of it.

WTF?!

At first I though it might have been someone throwing something, but again, it was humongous, and there's no way it could have been thrown from the street above, through the woods, down the hill into the river without breaking branches and rustling something.

One night a few weeks ago, while I fished the Deposit area of the Upper West Branch - also at dusk - I heard a loud "slap!" / splash that sounded to me to be a large fish, except for the "slap" part (which was every bit as loud as someone taking a boat oar and whacking the surface of the water with all their might) I commented to the guy who was fishing near me and he said it would have been a beaver swatting the water with his tail. There were no boats around.

Does this sound right? Beaver?

I never use flurocarbon, not a fan of it at all. I use mono all the time, and I catch fish for a living.

Softer wing material or smaller wings.

What are the crowds like up there (West Branch & Main Stem) on Fridays around Labor Day? I'm toying with a one-day trip up possibly on Sep 3rd or 10th and just wanted to know what to expect.

In my personal opinion only not based on any scientific fact,I think that any thing laying on the water surface on a bright sunny day will show up more than a cloudy day, and in slower water the fish always have more time to study your fly,and this is a big issue on places that are heavily fished like the Delaware where the fish get to see more flys in a week than we do all year.When dealing with picky slower water fish I always use a minimal dressed fly so I can use the lighter tippets.Years ago when the watered flow on the west branch was always 700 plus(before they fixed the valves)there was a lot more of the smaller flys we used 8 and 9x a lot ,sorry didn't mean to babble  Jim