Okay, using input from all y'all, here is a dogbone track plan I've devised based on comments from "the board" members. The plan is drawn using Atlas RTS 8.0. All I've done so far is the mainline and major yard/staging area. I still have spurs and what-not to add once I get the mainline nailed down.
Here is the space I have.
Here is the upper level
The yard in the upper left corner is actually (2) Walthers Ore Docks. The height from the switch to the dock is 5.5 inches. The rest of this level is flat for now. The red track to the right is leading down to the lower level. The two yard tracks are for the ore dock.
Here is the aforementioned lower level.
The circle to the left is a 4 level helix, 24 inch radius. The levels are 18 inches apart. The yard tracks are for staging.
Thoughts on the plan so far?