Okay, I think I have an idea of what you're struggling with. I guess in the picture with "big spot" you marked the area that was giving you a hard time? (Sorry, couldn't make sense of you explanation above... ) It looks like you drew in a ridge line but couldn't manage to "hide other stuff behind", if you know my meaning.

I'll draw a quick step-by-step of how I did my mountains. Might take few minuts, though.