Utah Code § 75-2-506: Choice of law as to execution.

A written will is valid if executed in compliance with Section 75-2-502 or 75-2-503 or if its execution complies with the law at the time of execution of the place where the will is executed, or of the law of the place where at the time of execution or at the time of death the testator is domiciled, has a place of abode, or is a national.