Thanks guys, I appreciate all the additional feedback.
Kevin, I'm on rivers and streams a lot, and I almost always carry a camera. If I'm engaged in something like fly fishing, as here, it's a small pocketable one (currently an Olympus TG-4 or Sony RX100). I'm always looking for water patterns, interesting rocks, and lighting in advance, to use if a situation arises and a subject cooperates. Oftentimes they don't. But with persistence, every now and then things come together, as I think they did here.