Yoop:
I'll throw my opinion in, but don't take it to the bank.
Based on 90.1, the structures would be NEC, and the local AHJs domain. We have this with the POCOs, ie: relay buildings at switching stations, office bldgs, trailers, etc.; but not anything that is 'utility'.
We don't have any types of 'mines' here, so this is not something I have any knowledge of.
