At first glance, I thought that certain parts of the trees on the right were far too dark but then I realised that your skill at shadow was amazing-- its not too dark at all.
The position of the rive is great. By glancing up along it, the view is drawn to all parts of the picture.
The "mirroring" of the trees on the river was well done, as was the foam along the edges. The sky is a beautiful colour. In fact, the colours in this picture is beautiful- the contrast and the variety is excellent
the color of the water is really beautiful, and I love the trees on the right side of the painting. They look terrific! I also think you did a really nice job with the sky, it's not too light or too dark. Altogether, fantastic work :]