The Southeast and Southwest corners are where the [switching] action is on the PER.
The East End industrial area:
The West End "Paint Factory":
The Northeast corner is a tunnel:
Concealed under the mountain is the track switch accessing Interchange in the next room.
The Northwest corner is pretty simple, mostly being storage for the Dinner Train:
Needs work but so does the whole pike. Scenery is pretty much schematic but as I get ideas it does slowly progress. Thinking about covering the mountain with Fall foliage.