Here is the 2013 Capitol Forest Trail and Road map image overlay. Makes for a nice relief map for route planning. If you get the free version of GE Pro, you can draw paths. Those paths can be used to tell you distance and elevation data.
Actually, while I would recommend Google Earth Pro to anyone whose system is rigorous enough not to get bogged down by it, the plain vanilla version of Google Earth also has the capacity to display the distance and profile of a path. (See the attached screen shot.)
I'm too old (and too far away) for back packing these days, but I still do a lot of fantasy camping. Downloading one of the USGS topographical maps can save you the time of making an image overlay. My favorite can be found >>HERE<<, and several other good ones are attached to replies.