At one side, Its great to see the planning, and at the other hand, it reminds me of Nifflas' video in game design where he teaches in front of a class. When he makes games, he says, over preparing can lead to not making the level at all. He recommends to do this kind of thing directly in the level editor.
But one thing is certain, the mountain idea you're having is much easier to draw on normal paper that way, than directly in the editor.