Is it this system? Utah Communications Authority Trunking System, Various, Multi-State - Scanner Frequencies
The scanner works best with just one site per system activated at a time.
It works best with only the control channel programmed into the site frequency list.
If the control channel doesn't rotate, leave just the active control channel programmed. If it does rotate, you will have to leave all of the possible controls in (I would add each one as it moves to a new control channel).
If you want to try to receive a different site, make an entire new system for that site. Put all of the talkgroups in a different scanlist from your main site. By the way, I recommend adding a wildcard, unless you just want to hear the broadcasts "approved" for your ears.
I've never been in the area to receive your system, nor have I read the forums about it. However, you might try going to the Site Options tab on the bottom right quadrant of the Trunked Radio Systems tab in EZ Scan. Set Trunking Tables to Custom. Click edit. A new window should appear. Click "Set Reband" at the bottom. Then click OK. Hopefully that will do the trick. Basically you are telling the scanner to look for the channel number on a newer band plan (spacing of frequencies), which is implemented to improve the efficiency of spectrum allocation.