Shouldn't this be in the Dakka P&M blogs section? Anyways, back on topic, I like the progress so far, but wouldn't it be easier if you just made a base for the hill? I mean the toothpicks would leave holes in your board, and if you wanted it in a different place, then there would just be even more holes....
Overall, I like the general look of it. Will you be making that divide between the styrofoam into a river or chasm or something like that?