Wyoming.

  1. Law
  2. CFR 40
  3. Protection of Environment
  4. Environmental Protection Agency
  5. Air Programs
  6. Designation of Areas for Air Quality Planning Purposes
  7. Section 107 Attainment Status Designations
  8. Wyoming.

Checkout our iOS App for a better way to browser and research.

§ 81.351 Wyoming.

Expand Table

Wyoming - 1971 Sulfur Dioxide NAAQS

[Primary and Secondary]

Designated area Does not meet primary standards Does not meet secondary standards Cannot be classified Better than national standards
Entire State X
Expand Table

Wyoming - 2010 Sulfur Dioxide NAAQS

[Primary]

Designated area1 Designation
Date2 Type
Albany County Attainment/Unclassifiable.
Big Horn County Attainment/Unclassifiable.
Campbell County Attainment/Unclassifiable.
Carbon County 4/30/2021 Attainment/Unclassifiable.
Converse County 4/30/2021 Attainment/Unclassifiable.
Crook County Attainment/Unclassifiable.
Fremont County (part) Attainment/Unclassifiable.
All areas west of the western border of Township 40North-Range 93West, T39N-R93W, and T38N-R93W, and south of U.S. Route 20.
Freemont County (remainder) 4/30/2021 Attainment/Unclassifiable.
Goshen County Attainment/Unclassifiable.
Hot Springs County Attainment/Unclassifiable.
Johnson County Attainment/Unclassifiable.
Lincoln County Attainment/Unclassifiable.
Natrona County Attainment/Unclassifiable.
Niobrara County Attainment/Unclassifiable.
Park County Attainment/Unclassifiable.
Platte County Attainment/Unclassifiable.
Sheridan County Attainment/Unclassifiable.
Sublette County Attainment/Unclassifiable.
Sweetwater County (part) Attainment/Unclassifiable.
All areas of the county east of U.S. Route 191.
Sweetwater County (remainder) 4/30/2021 Attainment/Unclassifiable.
Teton County Attainment/Unclassifiable.
Uinta County Attainment/Unclassifiable.
Washakie County Attainment/Unclassifiable.
Weston County Attainment/Unclassifiable.

1 Includes any Indian country in each county or area, unless otherwise specified. EPA is not determining the boundaries of any area of Indian country in this table, including any area of Indian country located in the larger designation area. The inclusion of any Indian country in the designation area is not a determination that the state has regulatory authority under the Clean Air Act for such Indian country.

2 This date is April 9, 2018, unless otherwise noted.

Expand Table

Wyoming - Carbon Monoxide

Designated Area Designation Classification
Date1 Type Date1 Type
Statewide Unclassifiable/Attainment
Albany County
Big Horn County
Campbell County
Carbon County
Converse County
Crook County
Fremont County
Goshen County
Hot Springs County
Johnson County
Laramie County
Lincoln County
Natrona County
Niobrara County
Park County
Platte County
Sheridan County
Sublette County
Sweetwater County
Teton County
Uinta County
Washakie County
Weston County

1 This date is November 15, 1990, unless otherwise noted.

Expand Table

Wyoming - Ozone (1-Hour Standard)2

Designated area Designation Classification
Date1 Type Date1 Type
Statewide Unclassifiable/Attainment
Albany County
Big Horn County
Campbell County
Carbon County
Converse County
Crook County
Fremont County
Goshen County
Hot Springs County
Johnson County
Laramie County
Lincoln County
Natrona County
Niobrara County
Park County
Platte County
Sheridan County
Sublette County
Sweetwater County
Teton County
Uinta County
Washakie County
Weston County

1 This date is October 18, 2000, unless otherwise noted.

2 The 1-hour ozone standard is revoked effective June 15, 2005 for all areas in Wyoming.

Expand Table

Wyoming - PM-10

Designated Area Designation Classification
Date Type Date Type
Sheridan County:
City of Sheridan 5/4/2018 Attainment
Trona Industrial Area 11/15/90 Unclassifiable
Campbell County (part) 11/15/90 Unclassifiable
Converse County (part).
That area bounded by Township 40 through 52 North, and Ranges 69 through 73 West, inclusive of the Sixth Principal Meridian, Campbell and Converse Counties, excluding the areas defined as the Pacific Power and Light Area, the Hampshire Energy Area, and the Kennecott/Puron PSD Baseline Area - Powder River Basin.
Campbell County (part), That areabounded by NW1/4 of Section 27, T50N, R71W, Campbell County, Wyoming - Pacific Power and Light Area 11/15/90 Unclassifiable
Campbell County (part), That area bounded by Section 6 excluding the SW 1⁄4; E 1⁄2 Section 7; Section 17 excluding the SW 1⁄4; Section 14 excluding the SE 1⁄4; Sections 2, 3, 4, 5, 8, 9, 10, 11, 15, 16 of T48N, R70W and Section 26 excluding the NE 1⁄4; SW 1⁄4 Section 23; Sections 19, 20, 21, 22, 27, 28, 29, 30, 31, 32, 33, 34, 35 of T49N, R70W. - Hampshire Energy Area 11/15/90 Unclassifiable
Campbell County (part), That area described by the W 1⁄2SW 1⁄4 Section 18, W 1⁄2NW 1⁄4, NW 1⁄4SW 1⁄4 Section 19, T47N, R70W, S 1⁄2 Section 13, N 1⁄2, N 1⁄2SW 1⁄4, N 1⁄2SE 1⁄4 Section 24, T47N, R71W. - Kennecott/Puron PSD Baseline Area 11/15/90 Unclassifiable
Rest of State1 11/15/90 Unclassifiable

1 Denotes a single area designation for baseline area purposes.

Expand Table

Wyoming - 1997 Annual PM2.5 NAAQS

[Primary and Secondary]

Designated area Designationa Classification
Date1 Type Date Type
Casper, WY:
Natrona County (part) Unclassifiable/Attainment.
The portion within the City of Casper.
Cheyenne, WY:
Laramie County (part) Unclassifiable/Attainment.
The portion within the City of Cheyenne.
Evanston, WY:
Uinta County (part) Unclassifiable/Attainment.
The portion within the City of Evanston.
Gillette, WY:
Campbell County (part) Unclassifiable/Attainment.
The portion within the City of Gillette.
Jackson, WY:
Teton County (part) Unclassifiable/Attainment.
The portion within the City of Jackson.
Lander, WY:
Fremont County (part) Unclassifiable/Attainment.
The portion within the City of Lander.
Laramie, WY:
Albany County (part) Unclassifiable/Attainment.
The portion within the City of Laramie.
Riverton, WY:
Fremont County (part) Unclassifiable/Attainment.
The portion within the City of Riverton.
Rock Springs, WY:
Sweetwater County (part) Unclassifiable/Attainment.
The portion within the City of Rock Springs.
Sheridan, WY:
Sheridan County (part) Unclassifiable/Attainment.
The portion within the City of Sheridan.
Rest of State:
Albany County (remainder) Unclassifiable/Attainment.
Big Horn County Unclassifiable/Attainment.
Campbell County Unclassifiable/Attainment.
Carbon County Unclassifiable/Attainment.
Converse County Unclassifiable/Attainment.
Crook County Unclassifiable/Attainment.
Fremont County (remainder) Unclassifiable/Attainment.
Goshen County Unclassifiable/Attainment.
Hot Springs County Unclassifiable/Attainment.
Johnson County Unclassifiable/Attainment.
Laramie County (remainder) Unclassifiable/Attainment.
Lincoln County Unclassifiable/Attainment.
Natrona County (remainder) Unclassifiable/Attainment.
Niobrara County Unclassifiable/Attainment.
Park County Unclassifiable/Attainment.
Platte County Unclassifiable/Attainment.
Sheridan County (remainder) Unclassifiable/Attainment.
Sublette County Unclassifiable/Attainment.
Sweetwater County Unclassifiable/Attainment.
Teton County (remainder) Unclassifiable/Attainment.
Uinta County (remainder) Unclassifiable/Attainment.
Washakie County Unclassifiable/Attainment.
Weston County Unclassifiable/Attainment.

a Includes Indian Country located in each county or area, except as otherwise specified.

1 This date is 90 days after January 5, 2005, unless otherwise noted.

Expand Table

Wyoming - 2012 Annual PM2.5 NAAQS

[Primary]

Designated area1 Designation Classification
Date2 Type Date2 Type
Statewide:
Albany County Unclassifiable/Attainment
Big Horn County Unclassifiable/Attainment
Campbell County Unclassifiable/Attainment
Carbon County Unclassifiable/Attainment
Converse County Unclassifiable/Attainment
Crook County Unclassifiable/Attainment
Fremont County Unclassifiable/Attainment
Goshen County Unclassifiable/Attainment
Hot Springs County Unclassifiable/Attainment
Johnson County Unclassifiable/Attainment
Laramie County Unclassifiable/Attainment
Lincoln County Unclassifiable/Attainment
Natrona County Unclassifiable/Attainment
Niobrara County Unclassifiable/Attainment
Park County Unclassifiable/Attainment
Platte County Unclassifiable/Attainment
Sheridan County Unclassifiable/Attainment
Sublette County Unclassifiable/Attainment
Sweetwater County Unclassifiable/Attainment
Teton County Unclassifiable/Attainment
Uinta County Unclassifiable/Attainment
Washakie County Unclassifiable/Attainment
Weston County Unclassifiable/Attainment

1 Includes areas of Indian country located in each county or area, except as otherwise specified.

2 This date is April 15, 2015, unless otherwise noted.

Expand Table

Wyoming - 1997 24-Hour PM2.5 NAAQS

[Primary and Secondary]

Designated area Designationa Classification
Date1 Type Date Type
Casper, WY:
Natrona County (part) Unclassifiable/Attainment
The portion within the City of Casper.
Cheyenne, WY:
Laramie County (part) Unclassifiable/Attainment
The portion within the City of Cheyenne.
Evanston, WY:
Uinta County (part) Unclassifiable/Attainment
The portion within the City of Evanston.
Gillette, WY:
Campbell County (part) Unclassifiable/Attainment
The portion within the City of Gillette.
Jackson, WY:
Teton County (part) Unclassifiable/Attainment
The portion within the City of Jackson.
Lander, WY:
Fremont County (part) Unclassifiable/Attainment
The portion within the City of Lander.
Laramie, WY:
Albany County (part) Unclassifiable/Attainment
The portion within the City of Laramie.
Riverton, WY:
Fremont County (part) Unclassifiable/Attainment
The portion within the City of Riverton.
Rock Springs, WY:
Sweetwater County (part) Unclassifiable/Attainment
The portion within the City of Rock Springs.
Sheridan, WY:
Sheridan County (part) Unclassifiable/Attainment
The portion within the City of Sheridan.
Rest of State:
Albany County (remainder) Unclassifiable/Attainment
Big Horn County Unclassifiable/Attainment
Campbell County Unclassifiable/Attainment
Carbon County Unclassifiable/Attainment
Converse County Unclassifiable/Attainment
Crook County Unclassifiable/Attainment
Fremont County (remainder) Unclassifiable/Attainment
Goshen County Unclassifiable/Attainment
Hot Springs County Unclassifiable/Attainment
Johnson County Unclassifiable/Attainment
Laramie County (remainder) Unclassifiable/Attainment
Lincoln County Unclassifiable/Attainment
Natrona County (remainder) Unclassifiable/Attainment
Niobrara County Unclassifiable/Attainment
Park County Unclassifiable/Attainment
Platte County Unclassifiable/Attainment
Sheridan County (remainder) Unclassifiable/Attainment
Sublette County Unclassifiable/Attainment
Sweetwater County Unclassifiable/Attainment
Teton County (remainder) Unclassifiable/Attainment
Uinta County (remainder) Unclassifiable/Attainment
Washakie County Unclassifiable/Attainment
Weston County Unclassifiable/Attainment

a Includes Indian Country located in each county or area, except as otherwise specified.

1 This date is 90 days after January 5, 2005, unless otherwise noted.

Expand Table

Wyoming - 2006 24-Hour PM2.5 NAAQS

[Primary and Secondary]

Designated area Designationa Classification
Date1 Type Date Type
Casper, WY:
Natrona County (part) Unclassifiable/Attainment
The portion within the City of Casper.
Cheyenne, WY:
Laramie County (part) Unclassifiable/Attainment
The portion within the City of Cheyenne.
Evanston, WY:
Uinta County (part) Unclassifiable/Attainment
The portion within the City of Evanston.
Gillette, WY:
Campbell County (part) Unclassifiable/Attainment
The portion within the City of Gillette.
Jackson, WY:
Teton County (part) Unclassifiable/Attainment
The portion within the City of Jackson.
Lander, WY:
Fremont County (part) Unclassifiable/Attainment
The portion within the City of Lander.
Laramie, WY:
Albany County (part) Unclassifiable/Attainment
The portion within the City of Laramie.
Riverton, WY:
Fremont County (part) Unclassifiable/Attainment
The portion within the City of Riverton.
Rock Springs, WY:
Sweetwater County (part) Unclassifiable/Attainment
The portion within the City of Rock Springs.
Sheridan, WY:
Sheridan County (part) Unclassifiable/Attainment
The portion within the City of Sheridan.
Rest of State:
Albany County (remainder) Unclassifiable/Attainment
Big Horn County Unclassifiable/Attainment
Campbell County Unclassifiable/Attainment
Carbon County Unclassifiable/Attainment
Converse County Unclassifiable/Attainment
Crook County Unclassifiable/Attainment
Fremont County (remainder) Unclassifiable/Attainment
Goshen County Unclassifiable/Attainment
Hot Springs County Unclassifiable/Attainment
Johnson County Unclassifiable/Attainment
Laramie County (remainder) Unclassifiable/Attainment
Lincoln County Unclassifiable/Attainment
Natrona County (remainder) Unclassifiable/Attainment
Niobrara County Unclassifiable/Attainment
Park County Unclassifiable/Attainment
Platte County Unclassifiable/Attainment
Sheridan County (remainder) Unclassifiable/Attainment
Sublette County Unclassifiable/Attainment
Sweetwater County Unclassifiable/Attainment
Teton County (remainder) Unclassifiable/Attainment
Uinta County (remainder) Unclassifiable/Attainment.
Washakie County Unclassifiable/Attainment
Weston County Unclassifiable/Attainment

a Includes Indian Country located in each county or area, except as otherwise specified.

1 This date is 30 days after November 13, 2009, unless otherwise noted.

Expand Table

Wyoming - NO2 (1971 Annual Standard)

Designated area Does not meet primary standards Cannot be classified or better than national standards
Entire State X
Expand Table

Wyoming - NO2 (2010 1-Hour Standard)

Designated area Designationa
Date1 Type
Albany County Unclassifiable/Attainment.
Big Horn County Unclassifiable/Attainment.
Campbell County Unclassifiable/Attainment.
Carbon County Unclassifiable/Attainment.
Converse County Unclassifiable/Attainment.
Crook County Unclassifiable/Attainment.
Fremont County Unclassifiable/Attainment.
Goshen County Unclassifiable/Attainment.
Hot Springs County Unclassifiable/Attainment.
Johnson County Unclassifiable/Attainment.
Laramie County Unclassifiable/Attainment.
Lincoln County Unclassifiable/Attainment.
Natrona County Unclassifiable/Attainment.
Niobrara County Unclassifiable/Attainment.
Park County Unclassifiable/Attainment.
Platte County Unclassifiable/Attainment.
Sheridan County Unclassifiable/Attainment.
Sublette County Unclassifiable/Attainment.
Sweetwater County Unclassifiable/Attainment.
Teton County Unclassifiable/Attainment.
Uinta County Unclassifiable/Attainment.
Washakie County Unclassifiable/Attainment.
Weston County Unclassifiable/Attainment.

a Includes Indian Country located in each county or area, except as otherwise specified.

1 This date is 90 days after October 31, 2011, unless otherwise noted.

Expand Table

Wyoming - 1997 8-Hour Ozone NAAQS

[Primary and Secondary]

Designated area Designationa Category/classification
Date1 Type Date1 Type
Statewide Unclassifiable/Attainment
Albany County Unclassifiable/Attainment
Big Horn County Unclassifiable/Attainment
Campbell County Unclassifiable/Attainment
Carbon County Unclassifiable/Attainment
Converse County Unclassifiable/Attainment
Crook County Unclassifiable/Attainment
Fremont County Unclassifiable/Attainment
Goshen County Unclassifiable/Attainment
Hot Springs County Unclassifiable/Attainment
Johnson County Unclassifiable/Attainment
Laramie County Unclassifiable/Attainment
Lincoln County Unclassifiable/Attainment
Natrona County Unclassifiable/Attainment
Niobrara County Unclassifiable/Attainment
Park County Unclassifiable/Attainment
Platte County Unclassifiable/Attainment
Sheridan County Unclassifiable/Attainment
Sublette County Unclassifiable/Attainment
Sweetwater County Unclassifiable/Attainment
Teton County Unclassifiable/Attainment
Uinta County Unclassifiable/Attainment
Washakie County Unclassifiable/Attainment
Weston County Unclassifiable/Attainment

a Includes Indian Country located in each county or area, except as otherwise specified.

1 This date is June 15, 2004, unless otherwise noted.

Expand Table

Wyoming - 2008 8-Hour Ozone NAAQS

[Primary and Secondary]

Designated area Designation Classification
Date1 Type Date1 Type
Upper Green River Basin Area, WY:2 Nonattainment Marginal.
Lincoln County (part)
The area of the county north and east of the boundary defined by a line starting at the point defined by the intersection of the southwest corner Section 30 Range (R) 115 West Township (T) 27N and the northwest corner of Section 31 R 115 West T27N of Sublette County at Sublette County's border with Lincoln County. From this point the boundary moves to the west 500 feet to Aspen Creek. The boundary follows the centerline of Aspen Creek downstream to the confluence of Aspen Creek and Fontenelle Creek (in R116W T26N, Section 1). From this point the boundary moves generally to the south along the centerline of Fontenelle Creek to the confluence of Fontenelle Creek and Roney Creek (in R115W T24N Section 6). From the confluence, the boundary moves generally to the east along the centerline of Fontenelle Creek and into the Fontenelle Reservoir (in R112W T24N Section 6). The boundary moves east southeast along the centerline of the Fontenelle Reservoir and then toward the south along the centerline of the Green River to where the Green River in R111W T24N Section 31 crosses into Sweetwater County.
Sublette County
Sweetwater County (part)
The area of the county west and north of the boundary which begins at the midpoint of the Green River, where the Green River enters Sweetwater County from Lincoln County in R111W T24N Section 31. From this point, the boundary follows the center of the channel of the Green River generally to the south and east to the confluence of the Green River and the Big Sandy River (in R109W T22N Section 28). From this point, the boundary moves generally north and east along the centerline of the Big Sandy River to the confluence of the Big Sandy River with Little Sandy Creek (in R106W T25N Section 33). The boundary continues generally toward the northeast along the centerline of Little Sandy Creek to the confluence of Little Sandy Creek and Pacific Creek (in R106W T25N Section 24). From this point, the boundary moves generally to the east and north along the centerline of Pacific Creek to the confluence of Pacific Creek and Whitehorse Creek (in R103W T26N Section 10). From this point the boundary follows the centerline of Whitehorse Creek generally to the northeast until it reaches the eastern boundary of Section 1 R103W T26N. From the point where Whitehorse Creek crosses the eastern section line of Section 1 R103W T26N, the boundary moves straight north along the section line to the southeast corner of Section 36 R103W T27N in Sublette County where the boundary ends.
Rest of State and Rest of Indian Country Unclassifiable/Attainment

1 This date is July 20, 2012, unless otherwise noted.

2 Excludes Indian country located in each area, unless otherwise noted.

Expand Table

Wyoming - 2015 8-Hour Ozone NAAQS

[Primary and Secondary]

Designated area1 Designation Classification
Date2 Type Date2 Type
Albany County Attainment/Unclassifiable
Big Horn County 1/16/18 Attainment/Unclassifiable
Campbell County 1/16/18 Attainment/Unclassifiable
Carbon County 1/16/18 Attainment/Unclassifiable
Converse County 1/16/18 Attainment/Unclassifiable
Crook County 1/16/18 Attainment/Unclassifiable
Fremont County 1/16/18 Attainment/Unclassifiable
Goshen County 1/16/18 Attainment/Unclassifiable
Hot Springs County 1/16/18 Attainment/Unclassifiable
Johnson County 1/16/18 Attainment/Unclassifiable
Laramie County Attainment/Unclassifiable
Lincoln County 1/16/18 Attainment/Unclassifiable
Natrona County 1/16/18 Attainment/Unclassifiable
Niobrara County 1/16/18 Attainment/Unclassifiable
Park County 1/16/18 Attainment/Unclassifiable
Platte County 1/16/18 Attainment/Unclassifiable
Sheridan County 1/16/18 Attainment/Unclassifiable
Sublette County 1/16/18 Attainment/Unclassifiable
Sweetwater County 1/16/18 Attainment/Unclassifiable
Teton County 1/16/18 Attainment/Unclassifiable
Uinta County 1/16/18 Attainment/Unclassifiable
Washakie County 1/16/18 Attainment/Unclassifiable
Weston County 1/16/18 Attainment/Unclassifiable

1 Includes any Indian country in each county or area, unless otherwise specified. EPA is not determining the boundaries of any area of Indian country in this table, including any area of Indian country located in the larger designation area. The inclusion of any Indian country in the designation area is not a determination that the state has regulatory authority under the Clean Air Act for such Indian country.

2 This date is August 3, 2018, unless otherwise noted.

Expand Table

Wyoming - 2008 Lead NAAQS

Designated area Designation for the 2008 NAAQSa
Date1 Type
Whole State Unclassifiable/Attainment.

a Includes Indian Country located in each county or area, except as otherwise specified.

1 December 31, 2011 unless otherwise noted.

[43 FR 8964, Mar. 3, 1978]

Editorial Note

Editorial Note:

For Federal Register citations affecting § 81.351, see the List of CFR Sections Affected, which appears in the Finding Aids section of the printed volume and at www.govinfo.gov.


Download our app to see the most-to-date content.