Mineral rights as well as water rights are a nationwide thing. I have heard similar stories about mineral rights in Tennesee and Kentuckey, where mining companies have started coal mining under peoples' homes and there is nothing they can do about it. Several court cases have proved it.
I was required to have a title search on my 75x100 property before the bank would give me a mortgage, but if someone who had the land in their family since the 1800s it must be very hard to deal now with what their great great grandparents did. Let that be a lesson to anyone who sells the mineral rights to their land no matter how poor they are. You never know what is under your home. or what your grandchildren will have to deal with.