Who Shot The Sign?

The other day I was visiting Sam's Club, (as usual) and I could very clearly hear gun shots. As I investigated further I found this shooting range down a dirt road hidden well behind WalMart.

Respecting the warning sign I turned around and left the area but I couldn't resist taking a shot/photo of this sign that had been shot at with a shotgun. Perhaps someone just couldn't wait to get into the range first?