oil and gas royalty business code and type

I have several mineral and properties across the country and just started an LLC for these properties. In the process of filing my taxes, I was asked what business code and type I am wanting to use. I am at a loss as to what to use. Code 531390 (Real Estate or Real estate Activities doesn't seem to fit. What has everyone been using?

531190 is what i use on my LLC's since they are leasing real estate. closest I have come up with. There hasn't been any definitive help that I have found, and if you call two different people at a state or fed to ask, you will get two or three different answers.