These are both brilliant scenes. Since you are asking for opinions, though, here are some suggestions.
1) Perhaps add some dry grass or isolated, stunted trees in the deer scene? There should be some vegetation along the edge of the stream.
2) The water surface is perhaps too smooth, and the water itself is too blue? The edge of the water – where it meets the shore – also seems too smooth. If you used a mask, you might try increasing its size so the water surface slightly intersects the terrain.
3) Also, perhaps introduce some texture into the exposed rock walls – strata, or some subtle fractal shading – just to make them look more natural.
3) The haziness and light angle of the second image are beautiful, but the clear blue sky seems out of place. Perhaps a layer or two of light clouds might be added to complement the haze? Maybe not, though – this might just be a matter of personal taste.
These are very minor points. Your work is excellent.