(1)
(a) The legislative body of a county of the first class may adopt an ordinance designating an area located within the county as a mountainous planning district if the legislative body determines that:
(i) the area is primarily used for recreational purposes, including canyons, foothills, ski resorts, wilderness areas, lakes and reservoirs, campgrounds, or picnic areas within the Wasatch Range;
(ii) the area is used by residents of the county who live inside and outside the limits of a municipality;
(iii) the total resident population in the proposed mountainous planning district is equal to or less than 5% of the population of the county;
(iv) the area is within the unincorporated area of the county or was within the unincorporated area of the county before May 12, 2015; and
(v) the area includes land designated as part of a national forest on or before May 9, 2017.
(b) The population figure under Subsection (1)(a)(iii) shall be derived from a population estimate by the Utah Population Committee created in Section 63C-20-103.
(2)
(a) A county may adopt a general plan and adopt a zoning or subdivision ordinance for a property that is located within a mountainous planning district.
(b) A county plan or zoning or subdivision ordinance governs a property described in Subsection (2)(a).