	Introduction

Livestock grazing on federal lands primarily occurs on public lands managed by the Bureau of Land Management (BLM, in the Department of the Interior) and on National Forest System lands managed by the Forest Service (FS, in the Department of Agriculture). Both agencies operate under statutory principles of multiple use and sustained yield, with livestock grazing among generally authorized uses. The extent to which BLM and FS lands are protected and available for various land uses and activities is of perennial interest to Congress. This report provides data on the extent of livestock grazing in recent years to assist with congressional deliberations on uses of federal lands generally and availability of lands for livestock grazing in particular. However, it does not discuss the relative likelihood of any one of these factors to affect grazing trends at national, regional, or local levels. Data Information and Caveats

This report generally provides data on livestock grazing for BLM and FS from FY2002 to FY2016. The four categories roughly correspond with
the number of livestock operators, the number of grazing permits and leases held by these operators, how much grazing could have been authorized for use, and how much grazing was actually used. For the other three categories of data, livestock grazing on BLM land was the same or somewhat less in FY2016 than in FY2002. FS had relatively larger declines over the years examined for the other three categories of livestock grazing. Figure 1 illustrates the changes in the numbers of BLM livestock operators and grazing permits and leases from FY2002 to FY2016. The number of active permits averaged 6,601. During the period of analysis, the agencies also experienced different patterns and amounts of change in the four categories of data. The amount of grazing used increased for both agencies from FY2002 to FY2016, but the increase was higher for BLM (5.2%) than for FS (1.1%). Grazing use was based on the amount of time livestock spent on the range, as measured in AUMs or HD-MOs. With regard to the number of livestock operators, BLM started and ended the FY2002-FY2016 period with nearly the same level, with some fluctuation in between; by contrast, FS livestock permittees decreased steadily from FY2006 to FY2016 and ended the period down 12.4%. By contrast, FS active permits decreased steadily from FY2006 to FY2016 and by a larger amount—12.5% overall. With regard to the amount of grazing that could have been used, the BLM's AUMs declined between FY2002 and FY2016 by 2.6%, whereas FS's HD-MOs ended the same period down by 18.4%. The size of the change in livestock grazing on BLM and FS lands depends in part on the length of the period examined. For example, although AUMs used on BLM lands increased by 5.2% over the last 15 years, over the past several decades they declined significantly—about 52.2% from the 1954 level of 18.2 million AUMs. Changes in grazing on BLM and FS land nationally reflect a variety of different conditions on rangelands in diverse locations. Similarly, no examination was made of the effect of change in particular areas on the national levels reflected in this report. However, national grazing changes identified herein can be attributed to a variety of factors, including amendments to agency land use plans to accommodate other land uses, such as increased recreation.
Livestock grazing on federal lands primarily occurs on lands of the Bureau of Land Management (BLM, in the Department of the Interior) and the Forest Service (FS, in the Department of Agriculture). Both agencies manage lands under sustained-yield and multiple-use principles, with livestock grazing among generally authorized uses. Congress continues to be interested in the extent to which BLM and FS lands are protected and used for a variety of activities, including livestock grazing. This report provides data on the extent of livestock grazing in recent years to assist with congressional deliberations on uses of federal lands generally and decisionmaking on the availability of lands for livestock grazing in particular.
This report generally provides data for 15 years, from FY2002 to FY2016, for four categories of livestock data. The four categories of data are similar but not identical between the agencies. The categories roughly correspond with the number of livestock operators, the number of grazing permits and leases held by these operators, how much grazing could have been authorized for use, and how much grazing was actually used.
Both agencies saw increases over the period in the amount of grazing used, based on the time livestock spent on the range. This time is measured in animal unit months (AUMs) for BLM and head months (HD-MOs) for FS. The increase in the amount of grazing was higher for BLM (5.2%) than for FS (1.1%).
For the other three categories of data, livestock grazing on BLM land was the same or somewhat less in FY2016 than in FY2002. FS saw relatively larger declines than BLM for these other three categories of livestock grazing. With regard to livestock operators, BLM started and ended the FY2002-FY2016 period with nearly the same number, with some fluctuation in between, whereas the number of FS livestock permittees decreased steadily from FY2006 to FY2016 and ended the period down 12.4%. Regarding the number of BLM permits and leases, there was a relatively small overall decline of 1.7% from FY2002 to FY2016. By contrast, the number of FS active permits decreased steadily from FY2006 to FY2016 and by a larger amount—12.5% overall. As for the amount of grazing that could have been used, BLM's AUMs declined by 2.6% between FY2002 and FY2016, whereas FS's HD-MOs declined by 18.4% over the same period.
The size of the change in livestock grazing on BLM and FS lands depends on the length of the period examined and the particular years of analysis. For instance, although AUMs used on BLM lands increased by 5.2% over the last 15 years, since 1954 there has been a 52.2% reduction in the number of AUMs—from 18.2 million to about 8.7 million.
Changes in grazing on BLM and FS lands nationally reflect a variety of different conditions on rangelands in diverse locations. The national changes can be attributed to various factors, including amendments to agency land use plans, resource protection needs and the long-term health of rangelands, the effect of weather (e.g., rain/drought) and fire on forage, voluntary nonuse by permit holders for a variety of reasons, and development on nearby private lands. The relative extent to which any one of these factors contributed to any national, regional, or local changes in grazing on federal lands is beyond the scope of this report.