It means people really had no idea what to make of it. I suspect it was a good thing. That exemption probably served as a great tax loophole much more it provided any kind of environmental benefit.
Which probably was quite popular in Emmons county.
For a strange thing in contrast though, Emmons was one of the weakest counties for ND's eminment domain overhaul in 2006 (basically an anti-Kelo v. New London initiative.) And the two counties bordering it to the east were the only two in the state where it failed. Don't ask me to explain that.