Utah Code § 17E-2-302
§ 17E-2-302. Lieutenant governor to record new county boundaries.
The office of the lieutenant governor shall modify county boundaries in accordance with: (1) Title 17, Chapter 61, Part 2, Consolidation of Counties; (2) Title 17, Chapter 61, Part 3, County Annexation; and (3) Title 17, Chapter 61, Part 4, Creating New Counties.