Lots of Purchase Inquiries

I have been getting calls and letters all summer about buying my mineral rights in McKenzie and Williams counties. This is after years of hearing almost nothing. Many of these offers are from companies I have never heard of, but others are from companies that have made ridiculous offers in the past and I won’t deal with (or who don’t offer direct deposit and like to mail my checks 60-90 days after the date of the checks). Similarly, my sister gets calls and offers even though she has hung up on these people after repeatedly telling them she has no interest in selling. I half suspect they call her because they know they won’t get my signature. Same with my aunt. What part of “no” don’t they understand? Does anyone have a sense of what is driving this push? I see some activity on the ND Oil site, but nothing which justifies this?