I noticed the same thing when I went camping up Springville Canyon at Kelly's Grove by Hubble Creek Golf Course. They have signs that say no guns. In fact, they have the rules posted on their website
Sprinville Canyon Campground rules. It is owned by the city of Sprinville, but this didn't stop me from carrying my gun. They need to change it to the discharge of any weapon is illegal.
I say we use the Contact Us links on their websites and let them know the law. Can we get some references to the state code to use in our email?