Awesome work Ryan!
This image looks quite alike my "brand new day" image, regarding colorpalette (rocks and grasses), displacements (cracks, mountains etc.),texturing and rendertimes...lol
However, I think this image "breathes more atmosphere". Your postwork-techniques certainly add to this.
The cloud looks very good and I like the way how you handled the lighting under the cloud. Any special trick for that?
I don't have any crits regarding the upper 2/3 of the image. It all looks damn good
The foreground could use little work. Like Richard said some of the flowers, especially in the left foreground for me, could be less prominent. This can sound a bit nutpicking, I don't intend to
The other thing I would add/change is the underwater-surfacing. Maybe some nicely displaced boulders would be great!
Martin