This theme shows Herd Management Areas (HMAs) in Idaho. Wild horses are managed in accordance with the Wild Free-Roaming Horse and Burro Act of 1971, which gives the Bureau of Land Management (BLM ) the responsibility to protect wild horses while ensuring their populations are in balance with the ecological capacity of public lands. This data set contains six herd management areas (HMAs). Four herd management areas are located in the Boise District, one HMA is located in the Twin Falls District and one HMA is located in the Idaho Falls District. BLM studies each HMA to determine how many wild horses the area can support while providing for other land uses and resource values. The overall capacity of the HMA to support wild horses is called its Appropriate Management Level (AML). All of Idaho's Herd Management Areas are managed for wild horses; there are no burros. All Herd Management Areas need to be contained within an originally designated Herd Area. Management status can change based on changing conditions. Specific laws and regulations pertaining to the management of wild horses and burros are applied. The Bureau uses the term Herd Management Area; the Forest Service uses the term Wild Horse Territory. A campaign started in the 1950's to protect wild horses and burros led to aerial flight surveys in 1971 to determine where wild horses and burros occurred. On Dec. 18, 1971, Congress passed the Wild Free-Roaming Horses and Burros Act. At that time, wild horses and burros were found roaming across 53.8 million acres of Herd Areas, of which 42.4 million acres were under the Bureau of Land Management's (BLM) jurisdiction. Herd Areas were carried forward in land use plans and determinations were made as to whether or not to manage animals on these federal lands. Today the BLM manages wild horses and burros in 179 subsets of these Herd Areas (known as Herd Management Areas) that comprise 31.6 million acres, of which 26.9 million acres are under BLM management. No specific amount of acreage was “set aside” for the exclusive use of wild horses and burros under the 1971 Wild Free-Roaming Horses and Burros Act. The Act directed the BLM to determine the areas where horses and burros were found roaming and to manage them "in a manner that is designed to achieve and maintain a thriving natural ecological balance on the public lands." The law also stipulated in Section 1339 that "Nothing in this Act shall be construed to authorize the [Interior] Secretary to relocate wild free-roaming horses or burros to areas of the public lands where they do not presently exist." Of the 22.2 million acres no longer managed for wild horse and burro use 6.7 million acres were never under BLM management. Of the 15.5 million other acres of land under BLM management (numbers current as of July 25, 2011): 48.6 percent (7,522,100 acres) were intermingled ("checkerboard") land ownerships or areas where water was not owned or controlled by the BLM, which made management infeasible; 13.5 percent (2,091,709 acres) were lands transferred out of the BLM's ownership to other agencies, both Federal and state through legislation or exchange; 10.6 percent (1,645,758 acres) were lands where there were substantial conflicts with other resource values (such as the need to protect habitat for desert tortoise); 9.7 percent (1,512,179 acres) were lands removed from wild horse and burro use through court decisions; urban expansion; highway fencing (causing habitat fragmentation); and land withdrawals; 9.6 percent (1,485,068 acres) were lands where no BLM animals were present at the time of the passage of the 1971 Act or places where all animals were claimed as private property. These lands in future land-use plans will be subtracted from the BLM totals as they should never have been designated as lands where herds were found roaming; and 8.0 percent (1,240,894 acres) were lands where a critical habitat component (such as winter range) was missing, making the land unsuitable for wild horse and burro use, or areas that had too few animals to allow for effective management. For more information contact us at blm_id_stateoffice@blm.gov.