Incredible terraforming, great work!

Awesome terraforming!  I'm impressed!  ;)

The terrain is nice, only thing id suggest is your use of materials for the mountain; its kind of un-aesthetic and unrealistic. I'm assuming youre using global operations and using "fill with terrain type" "at or above" with feather (correct me if im wrong.) A better (but more confusing) method would be to use the "fill with terrain type" at a certain angle, and use multiple materials. Here is what I do:
1. Fill terrain with podzol, above 40 deg.
2. Fill with terrain dirt, above 42 deg
3. Fill with terrain gravel, above 44 deg
4. Fill with terrain stone, above 45 deg

This makes a mountain feel more natural as there is more of a transition between materials.

anyways, keep up with the good work, and feel free to contact me if you need any help or advice

Nice, Great job !