Appendix I – Areas of Critical Environmental Concern Criteria 

As part of the process for developing the Greater Sage-Grouse Resource Management Plan (RMP)/Land 

and Resource Management Plan (LRMP) (hereafter, land use plans [LUP]) Amendments, the U.S. 

Department of the Interior, Bureau of Land Management (BLM) planning team members reviewed all 

BLM administered public lands in the planning area to determine if any areas should be considered for 

designation as areas of critical environmental concern (ACEC) or if any existing ACEC designations 

should be modified or terminated. Only BLM-administered public lands can be considered for ACEC 

designation. 

Areas of critical environmental concern are BLM lands where special management attention is needed to 

protect important and relevant values. Special management attention refers to management prescriptions 

developed during preparation of an RMP or amendment expressly to protect the important and relevant 

values of an area from the potential effects of actions permitted by the RMP, including proposed actions 

deemed to be in conformance with the terms, conditions, and decisions of the RMP (BLM Manual 1613). 

To be a potential ACEC, a nominated area must meet the criteria of relevance and importance as outlined 

in 43 CFR 1610.7-2 and BLM Manual 1613. If the relevance and importance criteria are met, an area 

must be identified as a potential ACEC and considered for designation and management in the resource 

planning process. Designation is based on whether or not a potential ACEC requires special management 

attention in the selected plan alternative. 

To be eligible for designation as an ACEC, an area must meet the relevance and importance criteria 

described in 43 Code of Federal Regulations (CFR) 1610.7-2 and BLM Manual 1613. 

Relevance and importance are defined as follows: 

Relevance. There shall be present a significant historic, cultural, or scenic value; a fish or wildlife 

resource or other natural system or process; or natural hazard. 

Importance. The above described value, resource, system, process, or hazard shall have substantial 

significance and values. This generally requires qualities of more than local significance and special 

worth, consequence, meaning, distinctiveness, or cause for concern. A natural hazard can be 

important if it is a significant threat to life or property. 

An area meets the “relevance” criterion if it contains one or more of the following: 

1.	 A significant historic, cultural, or scenic value (including but not limited to rare or sensitive 

archeological resources and religious or cultural resources important to Native Americans). 

2.	 A fish and wildlife resource (including but not limited to habitat for endangered, sensitive, or 

threatened species; or habitat essential for maintaining species diversity). 

3.	 A natural process or system (including but not limited to endangered, nonsensitive, or threatened 

plan species; rare, endemic, or relic plants or plant communities which are terrestrial, aquatic, or 

riparian; or rare geological features). 

4.	 Natural hazards (including but not limited to areas of avalanche, dangerous flooding, landslides, 

unstable soils, seismic activity, or dangerous cliffs). A hazard caused by human action may meet 

the relevance criteria if it is determined through the resource management planning process that 

it has become part of a natural process. 

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An area meets the “importance” criterion if it further meets one or more of the following: 

1.	 Has more than locally significant qualities, which give it special worth, consequence, meaning, 

distinctiveness, or cause for concern, especially compared with any similar resource. 

2.	 Has qualities or circumstances that make it fragile, sensitive, rare, irreplaceable, exemplary, 

unique, endangered, threatened, or vulnerable to adverse change. 

3.	 Has been recognized as warranting protection to satisfy national priority concerns or to carry out 

the mandates of the Federal Land Policy and Management Act (FLPMA). 

4.	 Has qualities that warrant highlighting to satisfy public or management concerns about safety 

and public welfare. 

5.	 Poses a significant threat to human life and safety or to property. 

This report presents the completed evaluation forms for the nominated ACECs in the planning area. An 

ACEC that meets both relevance and importance criteria can be included in at least one management 

alternative analyzed in the LUP Amendments and EIS. 

Table I-1. Greater Sage-Grouse Core Habitat Area (Alternative B) Relevance and
 

Importance Evaluation
 

Area Considered: Albany, Campbell, Carbon, Converse, Crook, Fremont, Goshen, Laramie, Lincoln, 

Natrona, Niobrara, Park, Platte, Sublette, Sweetwater, Teton, Uinta, and Weston 

Counties 

General Location: Albany, Campbell, Carbon, Converse, Crook, Fremont, Goshen, Laramie, Lincoln, 

Natrona, Niobrara, Park, Platte, Sublette, Sweetwater, Teton, Uinta, and Weston 

Counties in Wyoming 

General Description: Priority habitat areas for Greater Sage-Grouse in Wyoming. 

Acreage: The total number of acres of core sage-grouse habitats on BLM/U.S. Department of 

Agriculture, Forest Service (Forest Service) administered lands is 9,876,565 acres. Of 

that total, 5,063,436 acres are BLM/Forest Service surface administration and would 

constitute the Public Proposed Sage-grouse Core Habitat ACEC. 

Values Considered: Greater Sage-Grouse habitat. 

Relevance Value 

Meets 

Value 

(Yes/No) 

Rationale for Determination 

A significant historic, 

cultural, or scenic 

value 

Yes Although not the intent of the ACEC, due to its size and proposed 

restrictions on oil and gas and wind energy development especially, other 

sensitive resources would also benefit. 

A fish and wildlife 

resource 

Yes Other than sage-grouse, the proposed ACEC area contains a mix of elk, 

mule deer, antelope, moose, winter, transition, parturition ranges and 

migration corridors, and elk feedgrounds; with some of the winter ranges 

in these key habitat areas being the terminuses of some of the longest 

intact migration routes in the lower 48 states. Sage-grouse brood rearing, 

nesting, winter concentration areas, and lek sites; pygmy rabbit habitats; 

sage-steppe songbirds nesting and brood-rearing occur throughout these 

primarily sage-steppe habitats. The sage-steppe habitats in the proposed 

core area is the most intact stands of habitat remaining for sagebrush 

obligate species many of which are considered BLM sensitive such as 

233
 
 

 

 

the pygmy rabbit, brewer’s sparrow, loggerhead shrike, and sage 

sparrow. 

A natural process or 

system 

Yes There are several areas of special status plant species within these sagesteppe habitat areas, such as Trelease’s milk-vetch, Cedar Rim thistle 

and meadow pussytoes. 

Natural hazards No There are no specifically identified natural hazards in the proposed sagegrouse key habitat areas. 

Importance Value 

Meets 

Value 

(Yes/No) 

Rationale for Determination 

More than locally 

significant qualities 

Yes The proposed ACEC covers over six BLM Field Office Areas and three 

Forest Service Districts, and includes a large portion of the Wyoming 

Basin ecoregion and its associated sagebrush-steppe vegetative 

community and critical Greater Sage-Grouse core habitat. It also includes 

smaller portions of the Greater Yellowstone ecosystem and the Great 

Plains/High Plains ecoregion. The Wyoming Basin and its sage-steppe 

vegetative communities have been subject to intense fragmentation as oil 

and gas, coal, uranium, transmission lines, and other development has 

crisscrossed these vegetative communities with roads, pipelines, 

wellpads, compressor stations, transmission lines, and other forms of 

development. This cumulative buildup over time has reduced habitat 

effectiveness to the point that the Greater Sage-Grouse has been 

identified as eligible for listing (but currently precluded) under the 

Endangered Species Act (ESA). 

Special qualities Yes Sage-steppe habitat conversion to agricultural operations and 

industrialization have limited the amount of suitable sage-grouse 

breeding, nesting, brood-rearing, and wintering habitats across Wyoming. 

In addition, continuous cycles of drought and competition for resources 

with domestic and wild ungulates have resulted in limitations and conflict 

for resources on the remaining habitats. 

Warrants national 

priority/FLPMA 

protection 

Yes These issues have been recognized by the above referenced ESA listing 

by USFWS, as well as by the BLM, which is undergoing an EIS 

amendment to incorporate greater management protections for sagegrouse and their key habitat areas throughout the Casper, Kemmerer, 

Newcastle, Pinedale, Rawlins, and Rock Springs planning areas and the 

Bridger-Teton National Forest, the Medicine Bow National Forest, and 

the Thunder Basin National Grassland. 

Safety/public welfare 

concerns 

No Qualities regarding safety and public welfare are not present within the 

areas nominated as potential ACECs for sage-grouse habitat. 

Poses a significant 

threat 

No Areas nominated as potential ACECs for Greater Sage-Grouse habitat do 

not pose a significant threat to human life and safety or to property. 

Table I-2. Greater Sage-Grouse Habitat Area (Alternative C) Relevance and Importance 

Evaluation
 

Area Considered: Albany, Carbon, Converse, Fremont, Lincoln, Natrona, Niobrara, Sublette, 

Sweetwater, Uinta, and Weston Counties 

General Location: Albany, Carbon, Converse, Fremont, Lincoln, Natrona, Niobrara, Sublette, 

Sweetwater, Uinta, and Weston Counties 

General Description: Audubon Important Bird Areas in Wyoming. 

234
 
 

 

 

 

 

 

Acreage: 3,645,897 acres within the project area was nominated by the WildEarth Guardians. 

Values Considered: Greater Sage-Grouse habitat, migratory birds. 

Relevance Value 

Meets 

Value 

(Yes/No) 

Rationale for Determination 

A significant historic, 

cultural, or scenic 

value 

Yes Although not the intent of the ACEC, due to its size and proposed 

restrictions on oil and gas and wind energy development especially, other 

sensitive resources would also benefit. 

A fish and wildlife 

resource 

Yes Other than sage-grouse, the proposed ACEC area contains bird 

migration corridors. Sage-grouse brood rearing, nesting, winter 

concentration areas, and lek sites; sage-steppe songbirds nesting and 

brood-rearing occur throughout these primarily sage-steppe habitats. The 

sage-steppe habitats in the proposed core area contains the most intact 

stands of habitat remaining for sagebrush obligate species, many of 

which are considered BLM sensitive such as brewer’s sparrow, 

loggerhead shrike, sage sparrow, and waterfowl important areas. 

A natural process or 

system 

Yes There are several areas of special status plant species within these sagesteppe habitat areas, such as the Trelease’s milk-vetch, Cedar Rim 

thistle, and meadow pussytoes. 

Natural hazards No There are no specifically identified natural hazards in the proposed sagegrouse key habitat areas. 

Importance Value 

Meets 

Value 

(Yes/No) 

Rationale for Determination 

More than locally 

significant qualities 

Yes The proposed ACEC covers over six BLM Field Office Areas and three 

Forest Service Districts, and includes a large portion of the Wyoming 

Basin ecoregion and its associated sagebrush-steppe vegetative 

community and critical Greater Sage-Grouse core habitat. It also includes 

smaller portions of the Greater Yellowstone ecosystem and the Great 

Plains/High Plains ecoregion. The Wyoming Basin and its sage-steppe 

vegetative communities have been subject to intense fragmentation as oil 

and gas, coal, uranium, transmission lines and other development has 

crisscrossed these vegetative communities with roads, pipelines, 

wellpads, compressor stations, transmission lines and other forms of 

development. This cumulative buildup over time has reduced habitat 

effectiveness to the point that the Greater Sage-Grouse has been 

identified as eligible for listing (but currently precluded) under the ESA. 

Special qualities Yes Sage-steppe habitat conversion to agricultural operations and 

industrialization have limited the amount of suitable sage-grouse 

breeding, nesting, brood-rearing, and wintering habitats across Wyoming. 

In addition, continuous cycles of drought and competition for resources 

with domestic and wild ungulates have resulted in limitations and conflict 

for resources on the remaining habitats. 

Warrants national 

priority/FLPMA 

protection 

Yes These issues have been recognized by the above referenced ESA listing 

by USFWS, as well as by the BLM, which is undergoing an EIS 

amendment to incorporate greater management protections for sagegrouse and their key habitat areas throughout the Casper, Kemmerer, 

Newcastle, Pinedale, Rawlins, and Rock Springs planning areas and the 

Bridger-Teton National Forest, the Medicine Bow National Forest, and 

the Thunder Basin National Grassland. 

Safety/public welfare 

concerns 

No Qualities regarding safety and public welfare are not present within the 

areas nominated as potential ACECs for sage-grouse habitat. 

235
 
 

Poses a significant 

threat 

No Areas nominated as potential ACECs for Greater Sage-Grouse habitat do 

not pose a significant threat to human life and safety or to property. 

Map I-1. Proposed Audubon Important Bird Areas, Area of Critical Environmental
 

Concern
 

Table I-3. Pinedale Greater Sage-Grouse Relevance and Importance Evaluation 

Area Considered: Beaver Ridge, Fontenelle Creek, East Anticline 

General Location: Sublette and Lincoln Counties, Wyoming 

General Description: Priority habitat areas for Greater Sage-Grouse. 

Acreage: 54,800 

Values Considered: Greater Sage-Grouse priority habitat, big game migration, cultural resources, big game 

crucial winter range. 

Relevance Value 

Meets 

Value 

(Yes/No) 

Rationale for Determination 

A significant historic, 

cultural, or scenic 

value 

Yes Native Americans historically knew the Green River as "Seed-ska-dee," 

their name for the sage hens, or "prairie chickens." Prehistorically, the 

strutting grounds within the Pinedale Field Office held thousands of birds 

making them easy prey and a food staple for early people of the Green 

River Valley. 

A fish and wildlife 

resource 

Yes Core Area #1 (Beaver Ridge) at the north end of the field office is not 

only core sage-grouse habitat; it is also a major big game migration route 

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from the Hoback and Noble Basin areas to the Pinedale Anticline and 

Ryegrass areas. A great majority of the area is already classified “No 

Surface Occupancy.” Protecting this area from leasing will slow 

development and allow passage of big game through the area while 

traveling to and from winter and summer range. There are also numerous 

cultural attributes existing in the area. Two sites of note include Fort 

Bonneville, constructed in 1832; and Beaver Rim which was reported to 

be the location of several bison kill and procurement locales. Six 

Trapper’s Rendezvous where held in the area. This brought hundreds of 

people together for the purpose of restocking supplies selling their furs 

and the camaraderie of the group experience. Prehistoric sites in the 

area range from several bison kill and procurement locales to short term 

camps. In addition, there are numerous eligible sites along big game 

migration corridors. This area also contains Visual Resource 

Management (VRM) open space and is classified VRM II and III. 

Core Area #2 (Fontenelle Creek) is composed of a large block of sagegrouse core area located at the south end of the field office and 

extending into the Kemmerer Field Office. In addition to this area being 

sage-grouse core area, it contains a large block of Big Game Winter 

Range. This area also contains VRM II, open space, and no development 

attributes. 

Core Area #3 (East Anticline) is primarily located along the Mesa breaks 

and contains another very important big game and sage-grouse wintering 

area. A late prehistoric expression occurs in and along the Mesa breaks, 

making the area significant and in need of further study. Much of the area 

is currently under lease suspension. Since studies have indicated a steep 

downward trend in mule deer populations on the Anticline, continued 

protection of this area through lease suspensions would likely benefit 

mule deer and other populations of wintering wildlife. In addition to the 

area’s importance to wildlife, it also contains numerous prehistoric and 

historic sites. 48SU2019 is considered a NRHP eligible cultural site of 

spiritual significance to Native Americans and is located in this vicinity. 

The area is partially classified as VRM Class II with some III. 

A natural process or 

system 

Yes The nomination also meets the criterion for a natural system or process 

because of the condition of the sagebrush habitat in the nomination area. 

Natural hazards No No natural hazards are known. 

Importance Value 

Meets 

Value 

(Yes/No) 

Rationale for Determination 

More than locally No Although the area contains habitat for Greater Sage-Grouse 

significant qualities conservation, the area is not significantly unique or more important than 

other habitat areas in this region. 

Greater Sage-Grouse are distributed throughout the western United 

States. The portion of the distribution in Montana, Wyoming, North 

Dakota, South Dakota, Alberta, and Saskatchewan are designated as 

Management Zone I (Stiver et al. 2006). Management Zones are 

delineations of Greater Sage-Grouse populations and sub-populations 

within floristic zones with similar management issues. Within 

Management Zone I in Montana, Montana Fish, Wildlife and Parks 

designated core areas (MFWP 2009) and Wyoming Game and Fish 

Department (WGFD) has also designated core areas in Wyoming (WGFD 

2009b). In addition, Montana Audubon has also designated five important 

bird areas for sage-steppe associated birds, including Greater SageGrouse, in Montana, most of which are contained within the MFWP core 

areas. 

While all of these areas are considered important to Greater SageGrouse conservation, the areas are dispersed throughout the region and 

237
 
 

are not significantly unique to a specific region or planning unit. In 

addition, Greater Sage-Grouse habitat in these core areas is owned by a 

number of different entities and habitat on BLM lands is not distinct from 

habitat managed by other ownership. 

Special qualities No The area is not particularly fragile or sensitive to change as compared to 

other sites in Wyoming. 

Warrants national 

priority/FLPMA 

protection 

Yes Satisfies national priority concerns. 

Safety/public welfare 

concerns 

No No safety or public welfare concerns are known. 

Poses a significant 

threat 

No No significant threats. 

238
 
Map I-2. Proposed Pinedale Area of Critical Environmental Concern 

239
 
 

 

 

Table I-4. Newcastle Greater Sage-Grouse Relevance and Importance Evaluation 

Area Considered: Crook County 

General Location: Area is south of Moorcroft and west of Upton. It includes all lands except lands 

managed by the U.S. Forest Service or the State of Wyoming in all or parts of 

Townships 48-45 and Ranges 66-68. 

General Description: Priority habitat areas for Greater Sage-Grouse. 

Acreage: The proposed no leasing area covers approximately 79,179 acres. Of the 79,179 acres 

42,409 acres are federal mineral estate, 6,831 state minerals, and 29,939 acres of 

private mineral estate. 

Values Considered: Greater Sage-Grouse priority/core habitat. 

Relevance Value 

Meets 

Value 

(Yes/No) 

Rationale for Determination 

A significant historic, 

cultural, or scenic 

value 

No Although historic, cultural and scenic values occur widespread on public 

lands, the nominations did not highlight any such values as part of the 

nomination for sage-grouse habitat. A general reference to the presence 

of various resource values without specifying why the values are 

significant in the context of an ACEC does not provide rationale for 

meeting this criterion. 

A fish and wildlife 

resource 

Yes The area contains breeding, nesting, brood-rearing, and winter habitats 

for sage-grouse. There are currently three occupied leks within the 

proposed boundary of the No Leasing Area. The area proposed for No 

Leasing designation encompasses all of the seasonal and life cycle 

habitats required by sage-grouse during the year. 

Sage-grouse population declines throughout the west have caused 

serious concern for the species. Sage-grouse have been petitioned for 

listing under the ESA and is a designated Wyoming BLM sensitive 

species. 

While sagebrush communities exist throughout the West, the pressures 

on the sage-grouse habitat have threatened to elevate the species to a 

candidate for listing under the ESA. The area contained within the 

proposed No Leasing area is some of the best intact habitat within the 

Newcastle Field Office. 

A natural process or 

system 

No Although natural systems and processes occur on public lands, the 

sagebrush vegetation community and the various habitat requirements of 

Greater Sage-Grouse across its range are not comprised of plant species 

or communities as described in this criterion and were not highlighted as 

comprising a natural system. 

Natural hazards No The public lands nominated as potential ACECs do not constitute a 

natural hazard as described in this criterion. 

Importance Value 

Meets 

Value 

(Yes/No) 

Rationale for Determination 

More than locally 

significant qualities 

Yes The proposed No Leasing area has not been surveyed for sage-grouse 

leks and is believed to contain many leks that have not been identified. 

Radio collared grouse in the Newcastle Field Office have not been 

identified as migratory populations. The grouse in the proposed Raven 

Creek Special Management Area are most likely non-migratory 

populations. Grouse are planned to be collared in the spring of 2011 to 

determine migratory status and map seasonal habitat use. 

240
 
Special qualities Yes The areas nominated as potential ACECs have the following qualities 

described under this criterion: fragile, sensitive, irreplaceable, and 

vulnerable to adverse change. The resource on a range-wide basis is not 

rare, exemplary, unique, or endangered or threatened (i.e. listed 

species). 

Warrants national 

priority/FLPMA 

protection 

No Although conservation of Greater Sage-Grouse is of current national 

concern to the agency due to the warranted but precluded status in 

regard to listing by the USFWS, and initiation of the Greater Sage-Grouse 

planning strategy, the agency has been emphasizing Greater SageGrouse conservation since the late 1990s. In 2005, the BLM issued WOIM-2005-024 directing that sage-grouse conservation measures be 

included into all RMPs within the range of the species by 2015. At this 

time there exist no secretarial or executive orders or public laws 

identifying Greater Sage-Grouse as a national priority for protection 

beyond management of the species habitat which falls within the purview 

of implementation of the ESA and FLPMA. 

Safety/public welfare 

concerns 

No Qualities regarding safety and public welfare are not present within the 

areas nominated as potential ACECs for sage-grouse habitat. 

Poses a significant 

threat 

No Areas nominated as potential ACECs for Greater Sage-Grouse habitat do 

not pose a significant threat to human life and safety or to property. 

241
 
Map I-3. Proposed Newcastle Area of Critical Environmental Concern 

242
 
 

 

 

 

Table I-5. Greater Sage-Grouse General Habitat Relevance and Importance Evaluation 

Area Considered: Albany, Campbell, Carbon, Converse, Crook, Fremont, Goshen, Laramie, Lincoln, 

Natrona, Niobrara, Park, Platte, Sublette, Sweetwater, Teton, Uinta, and Weston 

Counties 

General Location: Albany, Campbell, Carbon, Converse, Crook, Fremont, Goshen, Laramie, Lincoln, 

Natrona, Niobrara, Park, Platte, Sublette, Sweetwater, Teton, Uinta, and Weston 

Counties 

General Description: General habitat areas for Greater Sage-Grouse in Wyoming. 

Acreage: The total acreage of Greater Sage-Grouse general habitats on BLM/Forest Service 

administered lands is 23,848,198 acres. Of that total, 11.6 million acres are 

BLM/Forest Service surface administration and would constitute the Public Proposed 

Sage-grouse General Habitat ACEC. 

Values Considered: Greater Sage-Grouse habitat. 

Relevance Value 

Meets 

Value 

(Yes/No) 

Rationale for Determination 

A significant historic, 

cultural, or scenic 

value 

Yes Although not the intent of the ACEC, due to its size and proposed 

restrictions on oil and gas and wind energy development especially, other 

sensitive resources would also benefit. 

A fish and wildlife 

resource 

Yes Other than sage-grouse, the proposed ACEC area contains a mix of elk, 

mule deer, antelope, moose, winter, transition, parturition ranges and 

migration corridors, and elk feedgrounds; with some of the winter ranges 

in these key habitat areas being the terminuses of some of the longest 

intact migration routes in the lower 48 states. Sage-grouse brood rearing, 

nesting, winter concentration areas, and lek sites; pygmy rabbit habitats; 

sage-steppe songbirds nesting and brood-rearing occur throughout these 

primarily sage-steppe habitats. 

A natural process or 

system 

Yes There are several areas of special status plant species within these sagesteppe key habitat areas, such as, the Trelease’s milk-vetch, cedar-rim 

thistle and meadow pussytoes to name a few. 

Natural hazards No There are no specifically identified natural hazards in the proposed sagegrouse general habitat areas. The area does contain rattlesnakes, 

stinging insects, roads in poor condition, etc. but at this scale and dealing 

with almost eleven million acres of BLM land, these hazards have not 

been specifically identified. 

Importance Value 

Meets 

Value 

(Yes/No) 

Rationale for Determination 

More than locally 

significant qualities 

No The proposed ACEC covers over six BLM Field Office Areas and three 

Forest Service Districts, and includes a large portion of the Wyoming 

Basin eco-region and its associated sagebrush-steppe vegetative 

community and Greater Sage-Grouse general habitat. It also includes 

smaller portions of the Greater Yellowstone ecosystem and the Great 

Plains/High Plains eco-region. The Wyoming Basin and its sage-steppe 

vegetative communities have been subject to intense fragmentation as oil 

and gas, coal, uranium, transmission lines, and other development has 

crossed these vegetative communities with roads, pipelines, wellpads, 

compressor stations, transmission lines, and other forms of development. 

It has been this cumulative buildup over time that has reduced habitat 

effectiveness to the point that the Greater Sage-Grouse has been 

identified as eligible for listing (but currently precluded) under the ESA. 

243
 
 

 

 

It is impossible to interpret the areas of protection based on the maps 

that were provided in the nomination. 

Special qualities No Sage-steppe habitat conversion to agricultural operations and 

industrialization have limited the amount of suitable sage-grouse 

breeding, nesting, brood-rearing, and wintering habitats across Wyoming. 

In addition, continuous cycles of drought and competition for resources 

with domestic and wild ungulates have resulted in limitations and conflict 

for resources on the remaining habitats. 

The combination of general habitat negates the benefits of the added 

protection needed in core habitat and may inadvertently increase 

fragmentation of core habitat as the complexities of overlapping resource 

values and projects of national interest intersect. 

Warrants national No These issues have been recognized by the above referenced TSA listing 

priority/FLPMA by USFWS, as well as by the BLM, which is undergoing an EIS 

protection amendment to incorporate greater management protections for sagegrouse and their core habitat areas throughout the Casper, Kemmerer, 

Newcastle, Pinedale, Rawlins, and Rock Springs planning areas and the 

Bridger-Teton National Forest, the Medicine Bow National Forest, and the 

Thunder Basin National Grassland. 

The general habitat within the project area in most cases has intensive 

mineral development and is held by production. The added value of 

managing the ACEC would not be fully realized due to the valid existing 

rights encumbering these habitats, which is largely why these areas were 

not included in the general habitat as a core area strategy by the State of 

Wyoming. 

Safety/public welfare 

concerns 

No Qualities regarding safety and public welfare are not present within the 

areas nominated as potential ACECs for sage-grouse habitat. 

Poses a significant 

threat 

No Areas nominated as potential ACECs for Greater Sage-Grouse habitat do 

not pose a significant threat to human life and safety or to property. 

244
 
Map I-4. Proposed Greater Sage-Grouse General Habitat Area of Critical Environmental 

Concern 

245
 
Background Information for All Nominations 

Greater Sage-Grouse are distributed throughout the western United States (Figure I-1). The portion of the 

distribution in Montana, Wyoming, North Dakota, South Dakota, Alberta, and Saskatchewan is 

designated as Management Zone I (Figure I-2) (Stiver et al. 2006). Management Zones are delineations 

of Greater Sage-Grouse populations and sub-populations within floristic zones with similar management 

issues. 

Figure I-1. Greater Sage-Grouse Distribution 

Source: Stiver et al. 2006 

Figure I-2. Greater Sage-Grouse Management Zones 

Source: Stiver et al. 2006 

246
 
 

Within Management Zone I in Montana, Montana Fish, Wildlife, and Parks (MFWP) has designated core 

areas6 (MFWP 2009) and WGFD has also designated core areas in Wyoming (Figure I-3) (WGFD 

2009b). 

Figure I-3. Greater Sage-Grouse Core Areas (Wyoming) 

6 Sage-grouse core areas are habitats associated with 1) Montana’s highest densities of sage-grouse (25% quartile), based on 

male counts and/or 2) sage-grouse lek complexes and associated habitat important to sage-grouse distribution (MFWP 2009). 

247