The prohibited use comes in, as I understand it, that , as with many National Parks, You are allowed by law to CCW, but yo are not allowed to discharge a firearm. (essentially saying you can't go target practicing anywhere) So in otherwords, you had better have a danged good reason for a discharge of any sort.
That being said, though, there have been instances of Self defense against animals (justified) where the gun owner was ticketed for the 'illegal' discharge.
I have personally had an 'official contact' with G&P LEOs (slight misinterpretation of signage) in which I declared my CCW status. They said thanks for teling us. and we all went about our business. One even made the comment that they view firearms a little differently than the officers in town might.
That contact made me feel more at ease carrying while camping and fishing.
