Docking operations complete. I added some silicon caulk to seal the base board and reinforced it for the next step.
Here is 100lbs of Silica sand as a proof of concept. This will also serve a secondary role as a zen garden when I am truly stressed out.
The primary purpose of the sand is to sculpt the terrain. I picked up this PVC rubber sheet for $15 from JoAnne fabrics to protect my felt game mats from the sand itself. I will paint one side brown or green to reduce the stark contrast.
Finally, here are some pics with minis to show the lay of the hills with my 6mm stuff.