This is some channel off the Potomac River at Great Falls on the Maryland side. I was standing on a bridge shooting down. It’s somewhere before the overlook on the falls themselves.
I am fairly certain that the rock is granite. Then again, I am not a geologist and I’m too lazy to Google. The image reminds you how water can carve through rock over the eons. You never really consider it until you pay attention to how the world is shaped by water in either its liquid form or its solid. This granite (assumed) been around since the Earth formed and still the water cut right through it.
There was some angst while editing this. I was going to make the image monochrome but it blew the water out. It became too hot on the conversion and burning it down turned it grey. I really wanted the water to be the focal point of the image. I also wanted the other stuff low key so I was stuck. I finally did the edit in color doing my normal routine. I pulled a trick out I learned awhile back and did a quick conversion using SilverFX playing with sliders until I got it to where I wanted it. I then brought it back into Photoshop and changed the layer to a luminosity mask. Adjusted the opacity until I got it where I wanted it. Just a quick dodge to areas too dark and called it done. It remained in color and I was happy.