In some counties in WV they only start taxing “severed” (when surface is sold and the minerals are retained) minerals when they start producing (when it has been reported to the State by the producer then to the county. In some counties they start taxing when the minerals are severed, starting separate tax listings for the surface and for the minerals. Sometimes they don’t separate them at the assessor’s office when severed (by mistake) and the surface owner pays everything. A different problem is when they are severed and “grandpa” keeps the minerals and gets a tax bill in his name. He gets old, dies without telling anybody to remember to pay the tax. The bill comes and is thrown away. Or grandpa’s address is not updated. Or grandpa had 10 children, one takes care of business like paying taxes then dies without telling. Etc. Eventually you might have 300 people who own an interest, when the oil and gas company comes to get leases and they have to sort it out. Etc.