Ice Mountains hills / 3D workflow

First time playing with 3D terrain creation in Gaea for my concept art, I had so much fun! ! I added some photo bash and paint-over in Ps, mostly for the clouds, water and ice. I created the back mountains from the inspiration of a linear chain of isolated mountains that we can observe in east of Montreal and Montérégie: The Monteregian Hills. But here, these are going out of the water... completely irreal!