There are several ways to accomplish the task of removing the mountains (lower the void areas) within your pattern.
My "Download" link, below, contains two zipped AVI lesson on the concepts involved.
The first is titled "Without pattern Editor-Part 1-Mountains". Michael Tyler and I spoke prior to the making of this lesson, and he suggested that this is a good concept for those without Pattern Editor.
The second lesson is titled "Pattern Editor Part 3". This is part of a series I've started on PE concepts.
Perhaps this will assist you and others.
AskBud