Utah Code Ann. § 75-1-401
(1) If notice of a hearing on any petition is required and except for specific notice requirements as otherwise provided, the petitioner shall cause notice of the time and place of hearing of any petition to be given to any interested person or the person's attorney if the person has appeared by attorney or requested that notice be sent to the person's attorney. Notice shall be given by the clerk posting a copy of the notice for the 10 consecutive days immediately preceding the time set for the hearing in at least three public places in the county, one of which must be at the courthouse of the county and:
(a)
(b) if the address, or identity of any person is not known and cannot be ascertained with reasonable diligence, by publishing: