I'm trying to flatten a base I have on Mercury, Myron Base to be more specific. The immediate base area was flattened, however, I am having an issue specifying at which elevation I should flatten. Below is an image of my current situation and my flattening code.

Code:
;;MyronBase
Ellipse 9 -84.679001 71.227997 700 700 -20000 -10000
