Section R307-405-4 - Area Designations(1) Pursuant to section 162(a) of the federal Clean Air Act, the following areas are designated as mandatory Class I areas: (a) Arches National Park,(b) Bryce Canyon National Park,(c) Canyonlands National Park,(d) Capitol Reef National Park, and(2) Pursuant to section 162(b) of the federal Clean Air Act, all other areas in Utah are designated as Class II unless designated as nonattainment areas.(3) No areas in Utah are designated as Class III.Utah Admin. Code R307-405-4