Is there a reason to join this organization? My uncle is a member but I'm not. When my dad died, we had a transfer of title upon death legal work in place. Don't want to pay $35/year if don't need to. We still have 50 acres unleased in Stephens County.
KJ, you just need to make sure your current name and current address are of record at each courthouse so you can be located by landmen. Your question has been asked before on this Forum. Use the search box at the upper right of this web page. Enter registry and you will be able to read many discussions.
Also ask your uncle if he was asked to supply the legals for his minerals and if he has been contacted by anyone using this service.