Thanks for the comments! I got the base and form from
www.summittaxidermy.com out of Alberta. The base is unique in that it is supported from underneath so that the whole rock sits out from the wall! It's mostly foam so you can carve it up and change the appearance easily. I was out hunting one day and saw this huge boulder covered in moss so I lifted up the edges and rolled the whole thing up and threw it in the truck! Imagine the wifes surprise when she came out to see what I'd shot!!!