While the state of Colorado doesn't explicitly prohibit gun owners from entering private buildings, it does have criminal trespass laws (
C.R.S. § 18-4-504 and
C.R.S. § 29-11.7-104 ) which allow property owners to decide to forbid firearms from their property.
MySecuritySign offers No Guns signs for Coloradans who don’t want firearms on their premises.
Outdoor use
Nice sign