Normally I fish the Brazos standing waist deep in water. A very pleasant way to fish this time of year, but it does have one small drawback, I can't see fish unless they are practically between my feet because my line of sight is so low, my eyes being maybe three feet above the water, maybe two, depending..
Recently I've had an opportunity to fish the river from a boat with a raised platform. From that platform my line of sight is about ten feet above the water, give or take a bit as I am guesstimating here. What that does is it allows me to see fish at a distance. There's a slight drawback to that too, if I can see them they can see me and that makes them skittish, but I'll take skittish for sight casting any day. And I can cast a long way from up high like that.
Another big bonus is that I often see the fish approaching my fly, and even taking it. That is a real bonus right there. Casting in front of a cruising bass is like leading a bird with a shotgun, you have to take into account the rate of speed of the bass, and the water depth - then you have to calculate how far ahead of the bass to cast and how far beyond it - so that the fly sinks down to the bass' depth as you retrieve it and it comes across the bass' nose. It's all fun and I rarely get it exactly right, but when I do and when that bass takes - WOW!, just WOW! My heart takes off like a trip hammer.
But the main thing I have noticed from being up high is how many fish there are in the river. I knew it was full of fish, but I didn't realized just how full it is. Beyond the Carp and Drum and Catfish and Buffalo - of which there are gazillions - there are bass in HUGE numbers. Great Honking Big Bass Too! I'll see dozens an hour that will go eight to twelve pounds when we are in a good area. I'd say that there are about two hundred times more bass than I had thought, and I had thought that there were a lot of bass to begin with. You've heard of a target rich environment right? Well I know how to define that now.
Another thing I noticed is that I did accurately figure out the best places and conditions to find the bass in this river - I mean that where I had learned to look for them was correct, those places are where the bass are. If you are fishing the Brazos, or I'm sure most rivers, look for a deep spot that is isolated. A deep spot that is surrounded by a large amount of shallow water. That concentrates them. But wait, there's more to it than just a deep spot.
Prime bass holes also have downed trees in them, submerged logs with branches, AND there are trees overhanging the hole that provide shade. So find a (lonely) deep spot with downed tree(s) in it that has overhanging trees over it and you are on gold. This set of conditions, of necessity, means you'll be looking along the banks. A lonely deep spot out in the middle of the river holds lots of fish, but few if any of them will be bass.
Shade is a real key here - As the sun arcs across the sky you'll want to switch banks to fish the shade. Bass love shade as much as we do.
This stretch of the river is very clear water with a gravel/rock bottom. Perhaps in other rivers with cloudier water and/or mud bottoms you'd find a different pattern, I don't know, but I'd bet these conditions hold for any river and probably maybe for lakes too.
But I guarantee you that in the Brazos from PK down to Waco, this is how to find them.