The cumulative impacts discussion is organized according to the following six cumulative issues:

Cumulative Issue 1: The cumulative impact on air quality with regard to public health and welfare within the Planning Area and protected Class I areas outside the Planning Area.

Cumulative Issue 2: The cumulative impact of surface-disturbing and other activities that affect vegetation cover on water quality.

Cumulative Issue 3: The cumulative impact of management actions on habitat for wildlife and special status wildlife species, including greater sage-grouse.

Cumulative Issue 4: The cumulative impact of management actions on global climate change.

Cumulative Issue 5: Cumulative impacts of management actions and constraints on recreation opportunities.

Cumulative Issue 6: The cumulative impact of management actions and projected development on the economic and social conditions of local communities.

To focus the cumulative impact analysis, the BLM determined the six cumulative issues by using the approach described under Methods and Assumptions. Review of the EISs and associated plans for all 40 projects (Table 4-27) revealed that most reasonably foreseeable actions could be expected to produce environmental impacts similar to the incremental impacts identified for the RMP alternatives. Some resources (i.e., special status species, air quality) that could be affected by reasonably foreseeable future actions have substantial value relative to legal protection and/or ecological, economic, or social importance. Exceeding legal standards or thresholds protecting these resources is not anticipated from the cumulative impacts of BLM and non-BLM actions; however, the programmatic nature of most reasonably foreseeable actions prohibits precise prediction of cumulative impacts. As a result, subsequent environmental impact analysis during project implementation will include more detailed and site-specific analyses of cumulative impacts.

Cumulative Issue 1: The cumulative impact on air quality with regard to public health and welfare within the Planning Area and protected Class I areas outside the Planning Area.

Cumulative Impact Assessment Area

The Bighorn Basin and federal Class I areas within 100 miles.

Analysis of Cumulative Impacts

Base year (2005) and anticipated annual air emissions by alternative for project years 2015 and 2024 are organized by project scenario and resource as shown in Tables 4-30 through 4-38 (tables located at the end of Cumulative Impacts). These tables identify each anticipated emission category for projected BLM actions, projected non-BLM actions, and the cumulative total of these actions.

Typical sources contributing to potential cumulative impacts on air quality would include emissions from conventional oil and gas development, vehicle operations associated with mining activities, and general vehicular activity from local residents and tourism. In addition, open burning of agricultural fields, which is a traditional practice in the CIAA, would, along with wildland fires and prescribed burns, result in impacts on air quality from emissions of particulates and polyaromatic hydrocarbons and temporarily reduce visibility in areas. Permitted stationary sources of air emissions, such as the Western Sugar factory in Lovell, Wyoming would also continue to contribute to cumulative impacts on air quality.

Overall, air quality in the Bighorn Basin is good. Some concentrated emission sources may have health impacts to certain local residents. The Washakie County Comprehensive Plan notes that a number of emission sources in the county contribute to poor air quality which can disproportionately impact the county’s senior and disabled population, who are more susceptible to dust and smoke than the general population (Washakie County 2004). Local policy that encourages land use and development that does not result in new, significant deteriorations of existing air quality would help to maintain current air quality, reduce air quality degradation, and protect public health. However, increases in population would likely bring more development and the potential for more emission sources that could degrade air quality in the Bighorn Basin.

BLM and non-BLM reasonably foreseeable actions are anticipated to increase emissions in the Planning Area over the life of the plan. For the Planning Area, the cumulative air quality impacts (as measured against NAAQS and WAAQS) are anticipated to have the same intensity on BLM- and non BLM-administered lands because it is assumed the density of activities are the same in both areas. This conclusion also assumes that cumulative impacts to air quality are equally distributed across the CIAA. Because of proposed development restrictions on BLM-administered land, the potential for adverse cumulative impacts to air quality are anticipated to be the least under Alternative B, followed by alternatives D and A. Cumulative emissions are projected to be highest under Alternative C due to fewer proposed development restrictions on BLM-administered land. Cumulative emissions within the Planning Area are not anticipated to result in air quality impacts that exceed NAAQS or WAAQS given the rather small amount of emissions (relative to other portions of the state of Wyoming where significant development is predicted) from BLM and other activities. The only exception may be ozone. The nearest ozone monitor to the Planning Area is located well outside of the Bighorn Basin, but showed levels close to the current standard (see Chapter 3 for additional information). However, the lack of available data makes it impossible to say with any certainty whether an exceedance of the standard would occur under any of the alternatives.

Cumulative Issue 2: The cumulative impact of surface-disturbing and other activities that affect vegetation cover on water quality.

Cumulative Impact Assessment Area

The Bighorn Basin and the reaches of Owl Creek.

Analysis of Cumulative Impacts

The Soil, Water, and Biological Resources - Vegetation sections in this chapter describe how surface disturbances, changes in vegetation cover, and other activities affect water quality by increasing or decreasing sediment loads in waterways or otherwise affecting water quality. In general, the more surface disturbance that occurs across the CIAA, the greater the potential impact to water quality. Adverse impacts to water quality would result from both short- and long-term disturbances, even though a majority of the area where surface disturbance is projected to occur on both BLM-administered land and state and private lands would be reclaimed. Sediment loading is of particular concern in Bighorn Lake, which provides for municipal and industrial water supplies and is a major recreation destination (USACE and BOR 2009).

Surface Water Quality

In the CIAA, stream-bank degradation and erosion and gully erosion, due to poor vegetative cover and surface disturbances, are the predominant sources of excessive sediment in waterways. On BLM-administered and private and state lands, surface disturbance caused by mineral and other development, the construction and maintenance of ROWs, and vegetation treatments (e.g., prescribed burns and mechanical fuels treatments) all contribute to short- or long-term losses of vegetation and increased sedimentation. In addition to surface-disturbing activities, impacts to water quality can result from a variety of other activities that can damage or remove vegetation and soil (e.g., improperly managed livestock grazing, OHV recreation, surface discharge of produced water, and concentrated use of riparian areas by wildlife). Sediment loading, along with other water quality issues such as the introduction of fecal coliform bacteria, occurs from private lands in the CIAA due to agricultural activities (e.g., irrigation runoff) and urban and rural subdivision development (Washakie County Conservation District 2006). Even given the high natural background sediment production in the Planning Area (USACE and BOR 2009; Washakie County Conservation District 2006), the South Big Horn Conservation District (2006) notes, “although flow from the rangelands and deserts contribute the majority and peak suspended sediment discharges to the rivers, irrigation wastewater significantly increases the sediment load in streams.” The cumulative impacts of BLM and non-BLM actions on water quality would likely be most pronounced along waterbodies with impaired water quality, such as those on the Wyoming DEQ’s 303(d) list (Wyoming DEQ 2008). The conditions of these waterbodies are partially linked to upland conditions, and they can carry large amounts of sediment downstream when surface flows occur.

As Table 4-26 shows, cumulative surface-disturbance acreage is projected to be highest under Alternative C and the lowest under Alternative B; Appendix T includes a breakdown of disturbance by activity. Proper management of surface-disturbing and other activities that can damage vegetation cover in the CIAA—through the application of guidance, such as the Standards for Healthy Rangelands and Guidelines for Livestock Grazing Management for the Public Lands Administered by the BLM in the State of Wyoming (Appendix N) on BLM-administered lands, or BMPs, such as those found in the National Range and Pasture Handbook and The Wyoming Forestry Best Management Practices: Forestry BMPs Water Quality Protection Guidelines on private lands (Appendix L)—would lessen sediment loading and associated adverse impacts to water quality. The application of BMPs on private land is not required in many instances and, therefore, their application would likely be inconsistent across the CIAA. In addition, the management under each RMP alternative (see Chapter 2 – Resource Management Alternatives) protects BLM-administered lands via restrictions on surface-disturbing and other activities and reclamation requirements of disturbed areas. This management would vary by alternative and would not apply to lands under state and private ownership. The scale and effectiveness of this protective management would be greatest under Alternative B, where the focus is on resource protection, and lowest under Alternative C, where the focus is on resource use and commodity production. As a result, cumulative impacts to water quality due to sediment loading are anticipated to be the most under Alternative C, followed by alternatives A, D, and B. However, even with the proper application of relevant guidelines, BMP, and restrictive management of resource uses across the CIAA, impacts to water quality from human activity would still continue to occur under all alternatives.

Programs related to education and coordination by Conservation Districts and county zoning regulations that attach minimum lot sizes to residential development may reduce sediment loading of streams in the CIAA. However, if trends associated with the subdivision of larger ranches into ranchettes continues across the Planning Area, and predicted population trends for Park and Big Horn counties occur (see Section 3.8.1 Social Values), increased building (e.g., residences or barns) and infrastructure construction, and the associated expansion of impermeable surfaces across the CIAA may lead to additional sediment loading of waterways. Depending on factors such as the type of development and the sediment contribution of the land use it replaces (e.g., agricultural rotational crops), such impacts may be beneficial.

Produced water from oil and gas development is regulated by the Wyoming DEQ, which establishes standards for water quality parameters such as total dissolved solid loads. Proper application of Wyoming DEQ water quality standards (Wyoming DEQ 2002) would lessen the potential for the introduction of water not meeting effluent limits, but this additional water would still result in adverse impacts to stream banks and gully erosion from altered flow regimes. The limited surface discharge of produced water anticipated in the Planning Area would limit the scale of these impacts.

Riparian Areas

In addition to general impacts from surface disturbance, BLM and non-BLM actions that affect riparian/wetland areas can result in substantial impacts to bank stability and the ability of vegetation to capture sediment and other water quality contaminants (see Section 3.1.4 Water). The majority of the surface lands along major waterways in the CIAA (i.e., the Bighorn River, Wind River, Clarks Fork of the Yellowstone River, and their associated tributaries, including the Nowood, Greybull, and Shoshone river systems) are privately owned. Of the 139,052 acres of riparian/wetland areas in the Planning Area, only 24,036 acres (17 percent) occur on BLM-administered surface. The large percentage of riparian/wetland areas on private lands means that actions by private landowners can have substantial impacts on the health of these systems and their performance of critical water quality protection functions. Programs and projects, such as those by County Conservation Districts, the National Resource Conservation Service, and county weed and pest districts, have had success in the implementation of proactive measures to improve riparian habitat and other vegetation and water sources (South Big Horn Conservation District 2007; Lumley et al. 2010). To manage riparian/wetland areas that occur on BLM-administered lands, alternatives A, B, and D apply proactive management measures that prohibit surface-disturbing activities in these areas and require active management of these to meet, or make progress towards meeting, PFC, DFC, or DPC. Management actions under alternatives B, D, A, and C would result in fewer beneficial impacts, respectively, to BLM-administered riparian/wetland areas. Actions by other entities to protect and restore riparian areas in the CIAA, coupled with protective management under alternatives B, D, or A may reduce cumulative adverse impacts to water quality by restoring functioning conditions in riparian areas. Such improvement would continue the current trend for these areas (see Section 3.3.3 Vegetation – Riparian/Wetland Resources).

Groundwater

The quality and quantity of groundwater in the CIAA is of concern as this water source makes up the majority of the municipal and residential water supply (South Big Horn Conservation District 2006; Big Horn County 2009). Alternatives proposed as part of this RMP revision would have impacts on groundwater through actions that allow or prohibit mineral development. In addition, municipal, mining, agricultural, and industrial use of this resource on state and private lands in the CIAA would affect groundwater quantity. Contamination of this resource from wastewater treatment and septic systems (Big Horn County 2009) and improper reinjection of produced water from oil and gas development are the principle groundwater quality concerns in the CIAA.

To limit adverse impacts to groundwater quality from wastewater, counties within the Planning Area are attempting to implement zoning restrictions and county level planning, such as the protection of sensitive groundwater areas in the Big Horn County Land Use Plan (Big Horn County 2009) through requiring larger residential lot sizes to reduce the concentration of wastewater discharge. Additionally, wells used for the reinjection of produced water require a permit from the Wyoming DEQ for construction and operation to insure the reinjected water does not enter into water bearing strata or resurface elsewhere. Though oil and gas development on state and private lands in the Planning Area is not anticipated to vary by alternative, Alternative C is projected to result in the greatest number of new federal oil and gas wells and, therefore, the greatest potential for cumulative adverse impacts to groundwater, followed by alternatives A, D, and B.

Cumulative Issue 3: The cumulative impact of management actions on habitat for wildlife and special status wildlife species, including greater sage-grouse.

Cumulative Impact Assessment Area

The Bighorn Basin.

Analysis of Cumulative Impacts

The condition of wildlife and special status wildlife species habitat is described in Chapter 3 – Affected Environment, and potential impacts to wildlife habitat from BLM-actions are described in Section 4.4 Fish and Wildlife Resources - Wildlife and Section 4.4 Special Status Species - Wildlife sections in this chapter.

Cumulative impacts on wildlife habitat would result primarily from surface-disturbing and other disruptive activities such as mineral development, road construction, vegetation treatments, rangeland improvements, and urban and rural expansion. These activities would result in short- and long-term impacts to wildlife habitat that may degrade and fragment habitat. Management actions to address the challenges associated with wildlife habitat impacts are listed by alternative in Chapter 2. Regardless of the alternative, the general approaches these management actions take to reduce impacts to wildlife habitat are the prohibition or restriction of certain resource uses and activities on BLM-administered land to control surface-disturbing and disruptive activities. These restrictions are generally applied to the following types of activities: oil and gas development, geophysical exploration, mineral materials disposal, renewable energy and ROW authorizations, and motorized vehicle use. Generally, the more surface disturbance and habitat loss from BLM actions, the greater the contribution to cumulative adverse impacts to wildlife and special status wildlife species. Of all the alternatives, Alternative C places the fewest restrictions on resource uses and surface-disturbing activities and would, therefore, result in the greatest adverse impacts to wildlife and special status wildlife species habitat.

Primary challenges for wildlife habitat management within BLM-administered land include poor habitat conditions, fire management, drought, increased development and urbanization, habitat fragmentation, OHV misuse, disease, hunter access, and the impacts of livestock grazing management on the frequency, quality, and composition of key forage species (see Chapter 3 – Affected Environment for more information). The challenges associated with impacts to wildlife habitat are anticipated to continue under all alternatives. Additionally, surface-disturbing activities, wildfires, spread of invasive species, and activities that remove vegetation are anticipated to impact wildlife habitat regardless of land ownership. Wildlife habitat impacts from non-BLM actions in the CIAA are primarily anticipated from urban and energy development and associated infrastructure (e.g., roads, pipelines, powerlines), although the intensity of development on private lands is not expected to vary by alternative.

As noted in Chapter 3, many wildlife populations spend considerable time on non BLM-administered lands and are therefore proportionately impacted by the management of these lands. Important wildlife habitat such as migration corridors and parturition and crucial winter ranges extend across the patchwork of land ownership in the CIAA. For example, the Planning Area contains 2,417,631 acres of big game crucial winter range, of which 47 percent is on non BLM-administered lands (BLM 2009a). Surface disturbance and other development (e.g., oil and gas) on these lands are not subject to the same restrictions designed to protect wildlife habitat on BLM-administered land and may increase the cumulative impacts on wildlife habitat. Given the varied land ownership pattern, protecting large blocks of intact habitat is a management challenge in the CIAA. The WGFD has, as part of its Strategic Habitat Plan, developed strategies to implement partnerships/projects with private landowners and land management agencies to preserve and restore habitat at the watershed or landscape level across land ownership boundaries (WGFD 2001). Within the Shoshone and Bighorn National Forests, wildlife specific management would protect habitat along the edges of the basin. For example, in the Bighorn National Forest Plan, the USFS applies seasonal restrictions on motorized travel routes to reduce disturbance in key big game areas such as birthing areas and winter ranges (USFS 2005a).

Increased residential development and an expanded network of roads in portions of the CIAA may contribute to a reduction in suitable wildlife habitat. While the majority of population growth would likely occur in population centers where most of the job opportunities exist, such as in Cody, Powell, and Worland, rural development may have a greater proportional impact if the development occurs near sensitive wildlife habitat. In Washakie County, for example, the rural population increased by approximately 17 percent during the 1990s, accompanied by an increase in the number of second homes in and against the mountains where much of the big game crucial winter range occurs (Washakie County 2004). The trend in second home development is not isolated to Washakie County, occurring along the mountains in other parts of the Bighorn Basin, and would result in an increase in cumulative impacts on wildlife and their habitat. Additionally, the practice of subdividing larger private parcels to support development of residential subdivisions and ranchettes (e.g., 35-acre parcels) is expected to continue and contribute to wildlife habitat impacts (Big Horn County 2009). As larger tracts of land adjacent to public lands are subdivided, the WUI and its associated effects (e.g., habitat degradation and fragmentation, fire suppression, and spread of invasive species) are expected to increase. Some tracts of BLM-administered land may become disconnected or isolated from other native habitats and ultimately adversely affect CIAA biological diversity. In addition, with multiple land owners in the WUI, management of resources and resource uses affecting wildlife habitat, including invasive species spread, fire, wildlife, livestock grazing, motorized vehicle use, and development are expected to be varied.

Oil and gas development would result in one of the greatest impacts to wildlife habitats. While reclamation and mitigation procedures would reduce the short-term impact from surface disturbance associated with oil and gas development, permanent facilities such as roads and well pads would result in long-term impacts. Cumulative impacts would be greater where mineral development is more intense, such as in Oil and Gas Management Areas designated under alternatives C and D, and on state and private land where fewer protections for habitat exist. Impacts would also be greater where oil and gas activity occurs in and around sensitive wildlife habitat such as crucial winter range. For example, several producing oil and gas fields overlap big game crucial winter range on private and state land along the Absaroka Front on the western edge of the Bighorn Basin. Cooperative management among landowners and the BLM in accordance with the Absaroka Front HMP would help to reduce the impacts to wildlife associated with mineral development in this area (BLM 1986a).

In general, cumulative impacts to special status wildlife species habitat would be the same as those for wildlife habitat. Surface-disturbing activities would tend to degrade and fragment habitat, having a greater impact where sensitive habitat and development occur. For example, many raptor nests occur near riparian areas, such as the Bighorn River corridor, where recreation and private development are common. On federal land, special status wildlife species would be protected by site-specific mitigation under the ESA and Wyoming BLM sensitive species guidance. However, on private and state lands, protection of non-federally listed species may not occur.

Cumulative impacts to greater sage-grouse habitat would result from surface-disturbing and other disruptive activities that result in loss of habitat and bird displacement. Restrictions that limit resource uses in greater sage-grouse habitat on BLM-administered land would reduce habitat loss, but would not prevent further habitat destruction from occurring on non BLM-administered land. Greater sage-grouse habitat on private and state lands would not receive the same level of protection and may result in greater habitat degradation. However, the core areas identified by the WGFD would help to limit development that may cause a decline in greater sage-grouse populations on state land (Wyoming Office of the Governor 2008). Applying resource constraints to limit disturbances within these core areas will protect suitable habitat for greater sage-grouse in the CIAA, reducing overall cumulative impacts to the species.

The greatest impacts on greater sage-grouse habitat would likely occur from mineral development and vegetation treatments that can remove large areas of sagebrush and increase the spread of invasive species. Impacts due to other factors such as hunting, predation, and farming may occur, but the scope of the impact would generally be smaller. For example, according to the Wyoming Greater Sage-Grouse Conservation Plan, farming areas make up only about 1.5 million acres in Wyoming, or 2.5 percent of the land area and currently only limited areas are being converted from sagebrush habitats to farmlands (Wyoming Sage-grouse Working Group 2003).

Cumulative impacts to wildlife and special status wildlife species habitat are anticipated to be least under Alternative B, which provides the most measures to minimize wildlife habitat loss and fragmentation and closes the most wildlife habitat to oil and gas development in the CIAA, followed by alternatives D, A, and C. The greatest adverse cumulative impacts to wildlife habitat are anticipated under Alternative C because this alternative allows the most development with the least restrictions to address wildlife habitat conservation on BLM-administered lands. For this analysis, habitat impacts from non-BLM actions are assumed not to vary across alternatives. In addition, habitat impacts from non-BLM actions on private lands may be greater than impacts on public lands based on the fact that privately held lands are subject to fewer restrictions and generally experience more development compared to public lands.

Cumulative Issue 4: The cumulative impact of management actions on global climate change.

Cumulative Impact Assessment Area

Global.

Analysis of Cumulative Impacts

The lack of scientific tools (models with sufficient spatial and temporal resolution) to forecast climate change even at regional scales limits the ability to quantify effects of current and future management on global climate change. Given this current state of climate change science, it is not yet possible to associate specific actions with specific impacts in a given area. As a result, a discussion of incremental impacts on climate change resulting from BLM actions when added to other past, present, and reasonably foreseeable future actions is not possible.

However, when added to past, present, and reasonably foreseeable future actions, the alternatives would result in overall differences in GHG emissions and contributions to climate change. Due to the lack of information for GHG emissions from past, present, and reasonably foreseeable future actions, cumulative impacts are analyzed qualitatively among the alternatives comparing management that would likely affect global climate change. Alternative C would result in the greatest cumulative impacts to climate change resulting from the most oil and gas development, the most surface disturbance, the least restrictions on livestock grazing, and the highest amount of fossil fuel combustion from motor vehicles, compared to the other alternatives. Alternative B would result in the least cumulative impacts to climate change due to the least amount of oil and gas development, the least projected surface disturbance, the most restrictions on livestock grazing, and the most conservation of biological resources that retain sequestered carbon and minimize emissions. Alternative D would result in greater cumulative impacts to climate change than Alternative B, less than Alternative C, and similar impacts to Alternative A (see Tables 4-3 and 4-4).

Implementation of the alternatives and other reasonably foreseeable future actions in the Planning Area would produce GHG emissions resulting in a minor contribute to climate change. As an indication of the scale of this contribution, projected CO2 emissions in 2018 resulting from BLM activities (Table 4-3) would result in approximately 0.5 percent of 2005 CO2 emissions in Wyoming (CCS 2007) and 0.005 percent of total 2008 CO2 emissions in the U.S. (EPA 2010). Any noticeable effects of climate change in any given area result from the cumulative aggregation of all worldwide GHG emissions, global climate patterns, and other forces. As a result, the cumulative impacts to climate change resulting from BLM management and other past, present, and reasonably foreseeable future actions in the Planning Area would likely have no measurable effect on global climate change.

Cumulative Issue 5: Cumulative impacts of management actions and constraints on recreation opportunities.

Cumulative Impact Assessment Area

The Bighorn Basin, plus the BLM Billings Field Office, Montana.

Analysis of Cumulative Impacts

Recreation (Section 4.6.5) and Comprehensive Travel and Transportation Management (Section 4.6.4) describe how management actions under each alternative affect recreation opportunities in the Planning Area. As with direct and indirect impacts, cumulative impacts would most likely occur from surface-disturbing activities (primarily related to minerals development), which change recreational settings, and from constraints, which limit access and recreational motorized vehicle use.

Resource development and surface-disturbing activities (e.g., oil and gas development, fire and fuels management) on BLM-administered lands and private and state lands can result in increased visual intrusions, noise, and visitor contacts that interfere with realizing desired beneficial outcomes and displace recreational users from their desired setting-specific areas. Recreationists seeking undisturbed landscapes are particularly affected by surface disturbance, especially in back country and primitive recreation settings. While much of this activity would be mitigated or avoided on BLM-administered lands regardless of the alternative, many of the restrictions discussed in this RMP do not apply to private and state lands in the CIAA. Cumulative impacts to recreation would therefore be greatest at the intersection of primitive or back country recreation areas and private lands, especially in areas where mineral potential or urban development potential is highest. Alternative B would result in the least cumulative surface disturbance and protects the most area suitable for primitive recreation (via LWCs, WSRs, and recreation management areas), followed by alternatives D, A, and C. As discussed under Cumulative Issue 3, cumulative impacts to wildlife can result from mineral and residential development (particularly in areas where such development overlaps important wildlife habitat). Development may displace big game populations, resulting in adverse impacts to opportunities for hunting, a major recreation activity in the Planning Area. Though management under the RMP cannot dictate management on private and state lands, protecting habitat on BLM-administered lands would benefit hunting across the CIAA by protecting important life-cycle (i.e., parturition) habitat for game species and thus insuring their continued presence. Alternative B would result in the smallest loss of wildlife habitat and the greatest benefits from proactive management actions in the CIAA (e.g., closing areas to oil and gas development), followed by alternatives D, A, and C respectively.

Potential long- and short-term cumulative impacts to recreation may also occur from land use restrictions established to protect sensitive resources. Development activities that improve legal access to public lands, establish new and improve existing roads, and increase opportunities for motorized travel may benefit recreational experiences for motorized vehicle (OHV) recreationists. Alternative C would be the most effective at increasing motorized recreation opportunities, followed by alternatives A, D, and B. Increasing resource use and development may increase traffic on some roads and trails and increase the potential for long-term conflicts between commercial and recreational use of these roads. Conflict may also occur if development on private lands adjacent to BLM-administered lands includes sensitive noise receptors (i.e., second home development or rural subdivisions); such development would likely occur regardless of the RMP alternative. Construction of pipelines, fences, and transmission lines would increase hazards to recreational motorized vehicle users and reduce public safety in certain areas. Management that results in a decrease in the amount of area available to motorized vehicle use on BLM-administered lands would be greatest under Alternative B, followed by alternatives D, A, and C. The availability of motorized recreation opportunities on private and state land is not anticipated to vary by alternative; however, increased access on adjacent BLM-administered lands may lead to increased use of non-BLM lands or, conversely, closing areas of BLM-administered land to motorized vehicles may displace these users to private or state lands.

Cumulative Issue 6: The cumulative impact of management actions and projected development on the economic and social conditions of local communities.

Cumulative Impact Assessment Area

The assessment area for cumulative social and economic conditions consists of the four counties that overlap the Planning Area.

Analysis of Cumulative Impacts

Analysis in this section primarily focuses on cumulative impacts related to oil and gas activity, ranching and livestock grazing, and quality of life, including nonmarket values.

The impacts of oil and gas drilling and production described in Section 4.8.2 Economic Conditions relate to activities only on BLM-administered surface and federal mineral estate within the Planning Area. However, oil and gas activity on private and state land is estimated to constitute a substantial portion of projected oil and gas activity in all alternatives (see Table 4-28 below). Specifically, in Alternative A, oil and gas drilling and production on state and private land would comprise about 31 percent of total activity; in Alternative B, about 50 percent; in Alternative C, about 28 percent; and in Alternative D, about 32 percent. Note that the percentage is greatest in Alternative B. The implication of this is that the activity on state and private land would partially mitigate the relatively lower oil and gas production on federal lands under Alternative B as compared to the other alternatives. The overall change in earnings, employment, and output would be proportionally smaller than the reduction in activity on federal lands would suggest. To see this, note that the analysis earlier in Chapter 4 showed $66.5 million in earnings and 1,121 jobs related to oil and gas drilling, completion, and production in Alternative A, and $30 million in earnings and 505 jobs for the same activities in Alternative B – a 55 percent reduction. The comparable figures incorporating state and private production are $96 million and 1,621 jobs for Alternative A, and $59.5 million and 1,004 jobs for Alternative B – a 38 percent reduction. While the reduction from Alternative A to B would still be substantial, the stability of state and private production would moderate the change in federal policy.

Similarly, the effect of oil and gas activities on state and private land moderates the changes in earnings and employment for alternatives C and D. In Alternative C, oil and gas activity on federal lands would create 13 percent more jobs and earnings than Alternative A, but incorporating state and fee lands would reduce this effect to a nine percent increase. In Alternative D, oil and gas activity on federal lands would create six percent fewer jobs and earnings than Alternative A, but incorporating state and fee lands would reduce this effect to a five percent decrease.

Under each alternative various management actions constrain mineral development on BLM-administered land for the protection of other resource values. These constraints can limit the mineral development activity on BLM-administered surface and mineral estate and constrict the minerals-based economy in the Planning Area. Table 4-29 summarizes the number of constrained federal wells and unconstrained non-federal wells for each alternative over the life of the plan.

The projected number of cumulative productive new wells is greatest under Alternative C (1,426) and the least under Alternative B (824). The percent increase/decrease from the number of new wells under Alternative A follows.

Increasing energy development and mining for mineral resources is likely to have a substantial social and economic impact within the Planning Area. As noted in the Economic Conditions section of this chapter, Alternative C is anticipated to result in the most substantial increase of economic opportunities with the highest projected job growth for the Planning Area followed by alternatives A, D, and B. Regional employment under Alternative C is also anticipated to average the greatest number of full and part-time jobs per year related to the oil and gas, livestock grazing, and recreation industries, which may result in beneficial impacts on quality of life. However, Alternative C may also result in adverse impacts to air quality, wildlife, and other resources that improve quality of life related to natural characteristics as priorities would be placed on the use of resources such as oil and gas development over the conservation of resources such as air quality and wildlife.

Comparatively, Alternative B would provide the least economic and social benefits as measured by jobs and income; priorities under this alternative are centered on conservation of land and existing environmental conditions. Alternative D would result in more opportunities than Alternative B, but fewer economic and social opportunities than Alternative C and Alternative A; the latter essentially represents the continuation of current trends. However, Alternative D would continue BLM’s current practice of allowing multiple uses, balancing the use of resources such as oil and gas reserves with the conservation of resources such as air quality, open space, and wildlife range areas while providing an increase in job opportunities dispersed geographically across the Planning Area. Overall, Alternative D updates BLM’s land and resource management guidelines in the Planning Area while preserving both job opportunities and nonmarket values associated with open space and the environment.

Past, present, and reasonably foreseeable future actions in the Planning Area and surrounding geographic areas would also affect both traditional economic measures (earnings, jobs, output) and nonmarket values in the Planning Area. For example, the BLM Lander Field Office RMP, which is being updated concurrent with the CYFO and WFO RMPs, would update BLM’s direction and management plans in the Lander Field Office, which includes some land in Hot Springs County as well as several neighboring counties. Thus, the choice of alternatives in the Lander RMP could directly affect social and economic conditions in the Planning Area for the Bighorn Basin RMP. However, based on past BLM actions and present policy of balanced management of land and resources, the combined effects within the Planning Area – either on traditional economic measures or nonmarket values – would not likely be different from those under alternatives A, B, C, and D in this planning effort.

A combination of market conditions and state and federal policy related to ranching and livestock grazing in Wyoming, and across the Rocky Mountain West, has created adverse economic conditions for many farms and ranches in the Planning Area. BLM management actions have the potential to help mitigate the effects of past and present trends that make livestock grazing more challenging, or to exacerbate those trends and further reduce the opportunities for livestock grazing operators. For example, some ranch owners raise money for retirement or other purposes by subdividing portions of their land into ranchettes and selling them to individuals. The sale of these ranchettes provides financial liquidity to ranchers who frequently have most of their assets in land, but generally results in increased building of fences, houses, and sometimes other structures (e.g., barns), changing the character of the landscape. Under all alternatives, this trend is likely to continue, because it is fundamentally related to (1) the nature of the ranching business (principally, the fact that most ranchers’ assets are in land, and the fact that profit margins are generally low and can turn negative in drought or other adverse conditions) and (2) state laws that govern property subdivision, under which county zoning laws cannot regulate subdivisions of 35 acres and larger. However, RMP alternatives that adversely affect the profitability of ranching could serve to increase this trend. Specifically, Alternative B would have an adverse impact on continued profitability of livestock operators, and under this alternative, the subdivision, sale, and development of ranchettes could accelerate. This would result in a substantial cumulative impact, and the contribution of the BLM action would be cumulatively considerable. Alternatives A, C and D would not be expected to exacerbate this cumulative impact.

Under all alternatives, however, potential cumulative impacts on livestock grazing operations could also result from a combination of activities and land uses occurring within the Planning Area primarily from surface-disturbing activities, human disturbances, and the presence of wildlife that compete with livestock for rangeland resources. Additionally, any increases in human population relative to increased job growth could create additional demands for recreational use of the public lands and could result in livestock displacement, increases in noxious weed infestation, and costs to operators and public land management areas. (However, only Alternative C would result in increased job growth compared to the current trend, and the increase would be small.)

Despite the potential for cumulative impacts resulting from various operations in the Planning Area, overall cumulative impacts of BLM and non-BLM actions are not anticipated to have long-term adverse impacts on livestock grazing on public lands, since anticipated impacts to grazing lands will occur gradually over the life of the plan, except in Alternative B where the impacts of livestock grazing withdrawals would be substantial for the reasons noted above. Additionally, the implementation of BLM’s mitigation guidelines, reclamation requirements, surface use restrictions, rangeland guidelines, vegetation treatments, and monitoring efforts would provide protection to forage resources on federal lands, which would help reduce overall impacts on livestock grazing resources and operations.