No...
Serious question... Sorta?
Figure how many cubic yards of the stuff gets dumped on roads every year.
No salt mined near me that I'm aware of?
I remember a while back some guys getting trapped in a salt mine. New York Maybe???
I pondered it myself John - the county i'm from in sw ohio has mountains of it piled up in reserve for winter every year . So ? there has a be some big empty salt mines somewhere .
ha hahaa - 
funny ...