How much “diligence” is required when trying to locate the heirs of mineral rights owners in Ohio, as stipulated by the Ohio Dormant Minerals Rights Act (DMA)? That issue was addressed, once again, last week–this time by Ohio’s 7th District Court of Appeals. The DMA requires a surface owner to exercise “reasonable due diligence” to ascertain the names and addresses of mineral holders and their heirs prior to serving notice of abandonment by publication. The question is, what is “reasonable due diligence”? Is there a common standard? The 7th District decided there is no common standard, and what’s reasonable in one case may not be reasonable in another. In other words, it all depends–and is unique in each case.