If you have a contested divorce in Utah, you are required to use a mediator that is on the Court Roster of Mediators for the State of Utah (see http://utcourts.gov/mediation/faq.html#choose). You can find a mediator on the Court Roster by going to the the state government website, http://utcourts.gov/mediation/divmed/public.asp to search by county to find a mediator that practices near you.
You have the right to choose your own mediator. The Court Roster has abbreviated bios that will give you an idea of their areas of expertise, and some have their own websites that you can read more about them and their mediation practice. Call a few likely candidates that you and your spouse/partner agree on and see if you can find a match. If a friend or family member has suggested a mediator, be sure to look them up on the Court Roster to make sure they are listed with the other Court approved divorce mediators.
Lawyers and retired judges who have taken the advanced domestic mediation training will also be listed on the roster. There are some very fine lawyer/mediators in Utah who are committed to the process of mediation and certainly do a good job, so if you are inclined to hire a lawyer/mediator, look for one who does at least as much mediation as litigation, if not more. Some attorneys have found they prefer practicing the non-adversarial process of mediation, and no longer do battle in the courtroom.