You give them too much credit, browns are a glutton for punishment. How big of a river you talking and how are you fishing them?
To be fair, I haven't invested much time to trying to figure them out. The one time I had success was very early and I was using a small spinner & worm on light spinning tackle. I'd cast ahead of the fish and let it sink diagonally with the current to in front of their noses. I mostly caught large suckers, but did catch one keeper brown. Live bait is not an option for me anymore (I've resolved never to use it again), so that's out the window...
I've only gone a few other times, and mainly threw crankbaits looking for smallies but with little luck. I usually wind up that way at a poor time though, and it is heavily pressured. I've caught bass on cranks in other rivers, but not here.
The river section I visit is perhaps a cast-length wide and goes from rapids to smooth (but fast) water. There are several boulders and obstacles within casting distance upstream, but I caught everything away from it.
I have to head up that way tomorrow morning anyway, so I might get up a bit earlier and try throwing some grubs on a 1/16th round-head jig looking for anything that will bite. Unless of course you have a better suggestion