Found it. Here's the link. Utah Department of Public Safety
"If an officer finds or sees a gun on your person during their contact with you, and you have not identified yourself as a permit holder in legal possession of a firearm, the officer may assume you are carrying the gun illegally and may take defensive action. "
Utah law says that if you inform PD of CCW, you should be OK. It also said that if you don't declare, PD is supposed to suspect you're doing something illegal and WILL go on the defensive. They said it better than I could.