I agree with the others. The snow on the ground, the vegetation and the water are excellent; the sky needs more work. Looking again, a very small point, but I would be inclined to do a little post-work in Paintshop Pro or Photoshop to touch up one area of snow on the closest rock: there is a parallelogram shaped "shadow" there that looks a bit unnatural (possibly an artefact from using too low a mesh density for such a close foreground terrain?) - I would soften the edges to break the straight lines up a bit.