Thanks for not being amused (it's really not a trick to climb the mountains and catch hungry fish - you just have to make the effort).
This is technical tailwater fishing and the best way to fish it is float with a guide.
Like all tailwaters, 70% of the biomass is midges (as surveyed by grad students on our research grant), but I always bust out to fish the BWO and caddis water.
For all you Euronymphers, this is productive water, and a US Team member home-bases here.
Dry fly action seems less than sporadic, but with time on the water, you can find places (usually shallow rutted dolomite) with regular surface action on the clock (most often kicked by our late afternoon drake hatch).
We have a December size 6 yellow hex that skittering a sofa pillow on that deep, slow hex water can put fish in a feeding frenzy.
Jimbo doing just that in some of my favorite pocketwater.
This is also where I shot those spawning rainbows in my previous post, though much farther upriver is the best water for wild-spawned fish.
Our last GRTU speaker was a Yellowstone guide, and one of our officers took her out looking for dry-fly fishing, and they had a bust day (of course it wasn't Jimbo or Dan...)
During her talk about Yellowstone, and I spoke with her afterwards, if you had just applied your Lava-Drops technique here to our visible BWO hatches (clouds of flies), you would have caught some nice fish.
Like all Texas hill country rivers, it's limestone, and the general structure is hard rutted dolomite with deep holes where the flagstone was lifted by floods, and gravel that moves around with floods. Because of that rutted dolomite, bring you wading staff to help keep you dry...
Here's one of our late afternoon dry fly spots (some on both sides of 3rd Xing) - you can't really see the rutted dolomite here
but you can here
here where Jake's fishing down from 4th Xing on River Road, a guide reported a 22" brown taken on a dry last winter
Jake has one of our typical tailwater rainbow bucks