Wyo. Stat. § 35-11-203 (2026)

(a) The following sources of air contaminants are subject
to the provisions of W.S. 35-11-203 through 35-11-212:

          (i) Any stationary source, or any group of stationary
sources located within a contiguous area and under common
control, that:

               (A) Has the potential to emit one hundred (100)
tons or more per year of any pollutant regulated under the Clean
Air Act and is a major stationary source as defined in section
302 of the Clean Air Act;

               (B) Has the potential to emit ten (10) tons per
year of any single hazardous air pollutant or twenty-five (25)
tons per year of any combination of hazardous air pollutants as
defined by section 112 of the Clean Air Act. Emissions from any
oil or gas exploration or production well (with its associated
equipment) and emissions from any pipeline compressor or pump
station shall not be aggregated with emissions from other
similar units, whether or not such units are in a contiguous
area or under common control, to determine whether such units or
stations are major sources; or

               (C) Is subject to the nonattainment area
provisions of title I, part D, of the Clean Air Act.

          (ii) Any other source of hazardous air pollutants,
including an area source, which the environmental protection
agency may designate pursuant to the provisions of section 112
of the Clean Air Act;

          (iii) Any source subject to the new source
performance standards promulgated by the environmental
protection agency pursuant to section 111 of the Clean Air Act;
          (iv) Any "affected source" subject to the acid rain
provisions of title IV of the Clean Air Act as defined in
section 501 of the Clean Air Act;

          (v) Any source subject to preconstruction review
permits pursuant to the prevention of significant deterioration
regulations promulgated by the environmental protection agency
pursuant to the Clean Air Act;

          (vi) Any other stationary source that the
environmental protection agency may designate by regulation
pursuant to authority granted under the Clean Air Act.

     (b) After the effective date of the operating permit
program authorized under W.S. 35-11-203 through 35-11-212, it
shall be unlawful for any person to violate any requirement of a
permit issued under the operating permit program or to operate
any source required to have a permit under this section, without
having complied with the provisions of the operating permit
program.

     (c) The department shall exempt any nonmajor source from
the obligation to obtain a permit under this section until the
environmental protection agency requires such sources to obtain
an operating permit in final regulations promulgated pursuant to
title V of the Clean Air Act.