Update:
I have added terrain and finished supports for the top of the box.
Left to complete are the sides of the box, supports for the rest of the coaster, and 3DS objects. I am working on the coaster as I post this.
There is a glitch in the game that places trees in random places past the editor's boundaries. The terraformer edits land past this point, making some of the randomly located trees on water [:D] You can see it in the back right of the picture above [:D]