OK, still hung up on my map. I found a good tile set, and played around until I figured out layer masks. Here is the result:
Most of tonights work went into the transition from the mountains into the desert to the north. Notice also that I gave the humans a valley in the south to be living in. Llaewyn mentions it in his initial rant at Mirian, so it needs to be there.
Still having way too much fun with this. :^)