Pursuant to a congressional request, GAO examined the Bureau of Land Management’s (BLM) performance in: (1) monitoring the impact of grazing on range conditions; and (2) taking action to change grazing conditions when needed. GAO found that: (1) BLM has only collected monitoring data for half of the 14,000 allotments that it should have completed within the last 5 years; (2) although BLM focused its limited monitoring attention on high priority allotments, it did not complete required monitoring within the required 5-year time frame for more than 300 allotments; (3) for 14 percent of the allotments BLM collected long-term trend data, but not the more specific short-term data needed to identify specific corrective actions; (4) BLM has not used its monitoring data to change grazing levels or practices; (5) BLM range managers attribute their inability to perform required monitoring and utilize data to staff shortages and the need to perform higher priority range management tasks; and (6) BLM grazing management decisions have lacked adequate documentation to support them.