How much “due diligence” must a landowner engage in when it comes to locating a long lost mineral rights owner in Ohio? According to Ohio’s Dormant Mineral Act (ODMA), the landowner who wants to reclaim mineral rights that were severed must (a) send a certified letter to the last known address of the rights owner, and (b) if that doesn’t work, publish a notice in local newspapers to try and find the long lost rights owner. After that, the landowner can reclaim the mineral rights (an oversimplification, but you get the idea).