Left nav - can't get it to consistenly line up to #content - Sample child theme

[computerkitten]

A customer wants to maintain the look of their current site...thus why this website looks this way that I'm working on.

I want to style the left navigation so that it doesn't move down the page when more content is added in the center. I've been fighting with this all morning.

The link is here:

http://echodevelopmentsite.com/beachrealtyinc/

Its not being recognized when trying to call it with the div#nav_menu-3. It seems to cut off the content then in the #content. I think its because its part of the div id# content-sidebar-wrap. I at one point got it to work on the home page only but then not on the "Why" link. It dropped down.

Is there a way to separate it out? How do I fix this? I just want to control both sidebars so they are equivalent in height for both sides no matter what changes in the middle #content section.

I used the free Sample that came with Genesis even though I do have a full Pro license. The sample one was more stripped down of course to build this different type of design.