Good point about the former salt mine, now massive underground storage facility that they drove through. There are a few in the Carthage, Springfield, Ozark area of MO. One interesting thing they didn't uncover during the show is the name of the company that operates the largest one in the area, and most likely the one they were filming inside of that aired on the show. The company's logo is interesting. You can check it out on their website: [link to www.omuvs.com]

Draw your own conclusions.