Before 1934, the General Land Office managed grazing on public lands outside forest perimeters. Congress initiated comprehensive management of these lands in 1934 when it passed the Taylor Grazing Act. The Grazing Service was established and charged with implementing the provisions of the Act. Specific tasks included establishment of a permit system, organization of grazing districts, fee assessment, and consultation with local advisory boards.

In 1946, the Grazing Service and General Land Office merged to form the BLM. Until Congress passed the FLPMA in 1976, the Taylor Grazing Act was the principle legislation used to administer livestock grazing on public lands. In 1978, Congress passed the Public Rangelands Improvement Act, which established a grazing fee formula that sets and adjusts annual fees for grazing on public land.

In 1985, the BLM established three categories for grazing allotments to identify areas with the potential need for management, and to prioritize workloads and the use of range improvement dollars. The BLM categorized allotments as Improve Existing Resource Conditions (I), Maintain Existing Resource Conditions (M), or Custodial Management (C). Criteria the BLM used to place allotments in category I included the amount of public land in the allotment; the willingness of lessees to invest in management; opportunities for constructing range improvements; the existence of grazing-related resource conflicts; the allotment had moderate to high forage production potential and was producing at low to moderate levels; the rancher or the BLM identified opportunities for improvement in range condition; range trend was static or downward; livestock management could be improved through water distribution; seasons of use or other factors; and opportunities for a positive economic return on public investments. The Glossary defines the criteria for placing allotments into the three categories; Appendix P provides a complete list of allotments in each of the categories.

In August of 1995, new regulations (43 CFR 4180) were enacted that changed BLM methods and administrative procedures for managing public lands. These regulations directed the establishment of standards for healthy rangelands and guidelines for livestock grazing management to “achieve properly functioning ecological systems for both upland and riparian areas.” The Secretary of the Interior approved Standards for Healthy Rangelands and Guidelines for Livestock Grazing Management for the Public Lands Administered by the BLM in the state of Wyoming in 1997.

Cattle are the primary livestock grazers on public lands, but grazers also include sheep, domestic horses, and small numbers of bison. Goats and sheep are sometimes authorized for the purpose of suppressing weeds. The relative number of these grazing animals has varied in response to their economic value as a commodity and their use in ranching operations.

Animal Unit Month Allocations

All livestock grazing allotments in the Planning Area are classified as perennial allotments. Term permits/leases authorize grazing use based on perennial vegetation. Grazing preference is attached to base property owned or controlled by a permittee or lessee. Base property in the Planning Area is land based.

At present, the BLM administers 687 grazing allotments covering 3.2 million acres in the Planning Area. Appendix P provides additional details about grazing allotments, including allotment number, allotment name, total federal acres, type of management, management category (M, I, or C), active use, and kind of livestock. Map 64 shows grazing allotments in the Planning Area.

Permitted use is the amount of forage available for livestock grazing under a permit or lease and is expressed in AUMs. Permitted use includes active use and suspended non-use. Active use is the maximum amount of forage generally available in any given year under a permit or lease. Due to fluctuating forage production, in any given year the BLM might authorize more or less forage for use for livestock grazing under a valid permit or lease due to fluctuating forage production.

The BLM determines stocking rates by monitoring the condition and amount of vegetation on a given site to ensure that adequate plant recovery time is provided and ample residual forage remains after livestock grazing to provide for healthy rangelands and other uses. Monitoring climate and water availability has resulted in forage availability adjustments, and by extension, adjustments to the numbers of livestock on the range. Predation also has resulted in changes in livestock type from sheep to cattle, and in some cases from cattle to horses. In other areas, disease-related concerns have resulted in the voluntary removal of domestic sheep in areas occupied by bighorn sheep.

Total active use for the Planning Area is 305,887 AUMs. The number of AUMs authorized annually in the Planning Area (Table 3–48) has remained fairly constant, but there has been a slight decline since 1989. This decline in authorized AUMs is due primarily to user requests for temporary non-use and unfavorable climatic conditions. For example, the gradual implementation of rest-rotation grazing systems leaves a portion of the allotment in non-use each year, contributing to the reduction. In addition, until 2009, which was a rare year of above-average rainfall, the Bighorn Basin had experienced drought conditions since 1999. The drought has resulted in less forage available for livestock use and the need for permittees/lessees to take voluntary non‐use. During drought years, livestock operators and the BLM work closely to tailor the adjustments in livestock use to meet the needs of the land and ranching operations. In addition, annual fluctuations in authorized AUMs can develop from user demands, climatic conditions, and/or from the collection of monitoring information.

Livestock grazing uses several resources directly and some resources indirectly. Livestock use rangeland vegetation for forage, but also might use riparian areas and wetlands for sources of water and forage. The BLM authorizes livestock grazing on specific allotments during different seasons. Grazing seasons vary with elevation and geographical change, resource needs, and user preference. Higher-elevation allotments are generally grazed during summer and fall. Lower-elevation allotments may be grazed during any season, but are generally used in fall, winter, and spring. Most of the allotments in the Planning Area are operating under grazing strategies that incorporate rest, seasonal rotations, deferment, and prescribed use levels that provide for adequate plant recovery time to enhance rangeland health. When rangelands are not meeting resource objectives, the BLM implements changes in grazing management.

According to the USDA National Agricultural Statistics Service (NASS), in 1994 through 1998, Wyoming accounted for 1.5 to 2 percent of the total number of cattle and calves within the United States. During this same period, Wyoming accounted for 8 to 9 percent of the total number of sheep and lambs in the United States. Nationally, as of January 2001 Wyoming ranked second in wool production, second in total number of sheep and lambs, and twenty-second in total number of cattle and calves.

The Stock Raising Homestead Act of 1916 authorized and a Secretarial Order created stock driveways for the specific purpose of creating lanes and reserving water sources for trailing livestock. Stock driveway withdrawals prohibited disposal of these lands, protected water sources, and placed limits on mining activity.

Use of stock driveways was an important part of livestock operations, especially for ranchers driving livestock between summer and winter ranges across the Planning Area. At present, 92,844 acres of public lands are identified as being part of the stock driveway system (BLM 2009a). Approximately 170 miles of stock driveways have been withdrawn for livestock trailing in the Planning Area. Stock driveways in use include predominantly the W-T, Nowater, and Rome Hill Livestock Trails and the Rawhide Allotment (03098). There are more designated livestock trailing routes that do not incorporate land withdrawals. Annual trailing use is over 2,200 AUMs (BLM 2008c).

There are a number of methods livestock managers use to evaluate rangeland health that can reveal trends in the composition or productivity of a plant community. The BLM monitors rangelands throughout the Planning Area as part of the landscape health assessment process.

Overall rangeland trends in relation to livestock grazing are stable or improving. The BLM manages many allotments under grazing rotations and seasons of use designed to meet soil cover and desired plant species growth requirements. Observations of old headcuts, roads, and other disturbances show that perennial species have increased in these areas once non-livestock disturbances ended. Generally, these observations have been confirmed in the rangeland health determinations completed to date. Where the BLM has identified existing livestock grazing or levels of use as a primary cause for rangeland health standards not being met, it has changed grazing use. The majority of allotments assessed to date meet, or are making progress towards meeting, the Wyoming Standards for Healthy Rangelands. Disturbances related to other ongoing resource uses (including oil and gas development and mining) can affect the observed trend.

Starting in 1998, the BLM began assessing grazing allotments for adherence to the approved Wyoming Standards for Healthy Rangelands (Appendix N) per the 1995 revision to the 43 CFR 4100 grazing regulations, and making management decisions in accordance with these standards (Appendix N). The BLM offers grazing permits and leases, and permittees/lessees accept them with the understanding that before reissuance, the BLM will evaluate resource conditions to determine if they conform to the standards for healthy rangelands approved by the Secretary of the Interior on August 12, 1997. The Standards for Healthy Rangelands and Guidelines for Livestock Grazing Management for the Public Lands Administered by the BLM in the state of Wyoming allow sustainable livestock grazing management to continue while simultaneously protecting watersheds, riparian and upland ecosystems, and wildlife habitat. Standards address the health, productivity, and sustainability of BLM-administered public rangelands and represent the minimum acceptable conditions for public rangelands. The standards apply to all resource uses on public lands. The BLM will determine their application as use-specific guidelines are developed. Standards can be synonymous with goals and are observed on a landscape scale. They describe healthy rangelands rather than important rangeland byproducts. The achievement of a standard is determined by observing, measuring, and monitoring appropriate indicators. An indicator is a component of a system the characteristics of which (e.g., presence, absence, quantity, and distribution) can be observed, measured, or monitored based on sound scientific principles.

From 1998 through the end of the 2010 fiscal year, the BLM had completed rangeland health evaluations for 308 allotments in the Planning Area (Appendix P). Of these, 168 allotments were found to meet or were making significant progress towards meeting Wyoming Standards for Healthy Rangelands 1, 2, 3, and 4. Allotments which had the Water Quality Standard of “unknown” are not considered as Not Meeting Standards. That status is a BLM policy unless the Wyoming DEQ provides specific information that waters in the allotment are not meeting state water quality standards. Including these allotments as “not meeting standards” would be misleading in terms of the current status of grazing allotments in the RMP. Allotment‐specific guidelines are being implemented to improve rangeland conditions in areas that do not meet standards. In most allotments not meeting standards, not all public lands were considered to be failing. In addition, many not meeting standards determinations were for reasons other than current livestock management (e.g., historic livestock grazing use, OHV use, oil field development, and mineral extraction). Of allotments not meeting these standards, 20 were due to current permitted livestock grazing management and all 20 have had corrective actions taken. Where current livestock grazing management has been identified as contributing to an allotment failing rangeland health standards, the BLM uses the Wyoming Guidelines for Livestock Grazing Management to direct new grazing management stipulations for the allotment.

Range improvement projects and grazing systems, collectively known as BMPs, and allotment management plans (AMPs) have been used in range management since the early 1970s. There are many older range improvement projects on public lands that appear to have never been authorized by the BLM. These consist primarily of reservoirs and fences. It is possible some of these projects were authorized, but their records are not available. In recent years the BLM has cost shared with other agencies and private organizations on some projects to reach mutual goals or objectives.

The BLM Range Improvement Project System database lists range improvement projects completed in the Planning Area. Since the completion of the Cody, Grass Creek, and Washakie RMPs, the BLM has initiated approximately 423 projects and 82,314 acres of vegetation treatments in the Planning Area (Table 3–49). In addition, it has modified or reconstructed several older projects. Projects include vegetative manipulation treatment projects using prescribed fire, mechanical treatments, seeding, or chemical treatments to modify plant communities. The BLM also has constructed fences, water developments, spring enclosures, and cattleguards. Range improvements are planned and designed to enhance rangeland health and wildlife habitat and to mitigate conflicts with other uses. In several projects, the BLM has replaced or modified existing fences to make it easier for wildlife to pass.

Management Challenges

Management challenges for the livestock grazing management program include water supply and distribution, forage production, forage quality, and topography. Water availability can have an important effect on the ability of livestock to properly utilize the range. Distribution of water affects the ability of the livestock to efficiently use the forage available in the allotment. Well-distributed water sources equates to efficient use of the grazing pasture, reducing the number of areas that are grazed too intensely or not used at all. Range suitability is related to the distance to water, slope, season of use, and class and kind of livestock. For example, the range is 100 percent suitable if it is within 1 mile of water and unsuitable if it is more than 2 miles from water (Holechek 1988).

Forage availability is also an important feature. Forage production affects the carrying capacity of the range for all uses and, more specifically, how many and how long livestock can remain on the range. The condition of the range affects forage quantity and quality. For example, a range dominated by appropriate cool-season bunchgrasses generally provides a better forage base than one dominated by invasive species. Surface-disturbing activities (e.g., mineral development) can reduce or change the status of forage in the Planning Area.