I would corp out some on the left so that the rock ends up in the upper left third - where the rule of thirds lines intersect. You will still get enogh of the river to lead my view to the rock and the sky beyond. Taking out some but not all of the underbruch at the bottom would help as well.
I would have cropped just a tad bit from the bottom, perhaps even given those red plants a hedge before I shot the shot. The river gives good depth to the image. The contrast in colors is nice. 6
Very pretty. This has enough variance in texture and color to really work as a landscape without a person or animal in it. The angle of the shot is well done too. Nice perspective.