List of BLM Herd Management Areas

Herd Management Areas (HMA) are lands under the supervision of the United States Bureau of Land Management (BLM) that are managed for the primary but not exclusive benefit of free-roaming "wild" horses and burros. While these animals are technically feral equines descended from that was originally domesticated, the phrase "wild horse" (and wild burro) has a specific meaning in United States law, giving special legal status to the descendants of equines that were "unmarked and unclaimed" on public lands at the time the Wild and Free-Roaming Horses and Burros Act of 1971 (WFRHBA) was passed. Horses that escaped or strayed from other places onto public lands after December 15, 1971 did not automatically become protected "wild horses". In 1971, free-roaming horses and burros were found on 53,800,000 acres (21,800,000 ha) of federal land. Today there are approximately 270 HMAs across 10 states, comprising 31,600,000 acres (12,800,000 ha). Additional herd areas (HAs) had free-roaming horse or burro populations at the time the Act was passed and some still have horse or burro populations today, but unlike the HMAs, they are not managed for the benefit of equines. In addition, some free-roaming equines protected under the WFRHBA are found on lands managed by the National Park Service (NPS), and United States Forest Service (USFS), where they are called wild horse territories (WHT). The BLM sometimes manages equine populations for other federal agencies, the USFS manages some of its own WHTs, and sometimes the agencies administer these areas jointly.

Equine population estimates in each HMA can vary significantly from year to year, depending on habitat condition in a given area,fecundity of the animals, or if a has occurred. Census-gathering methods also vary, and wild horse advocacy groups frequently question the validity of the population counts. Nonetheless, each HMA is given an Appropriate Management Level (AML), usually given as a range showing upper and lower limits. This is the BLM's assessment of the number of equines the land can sustain. When the population gets too high, some animals are removed and placed for adoption with private owners or sent to long-term holding facilities elsewhere. Since 1971, about 220,000 horses and burros have been adopted through the BLM.

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