Barb,
I’ve never owned a mobile home park that came with mineral rights where there is any potential for value in them. For example, at my parks in East Texas (one of th top oil producing counties in the U.S.) the mineral rights had been stripped off and sold in the 1920’s. This is in no way uncommon. In areas that have oil & gas activity, those rights are a marketable commodity normally sold by the farmer back in the early days. The reason so many park owners have mineral rights in the new horizontal-drilling activity areas is that they were considered worthless until recently so nobody stripped them out and sold them.