List of Bureau of Land Management Herd Management Areas

[6] Census-gathering methods also vary,[5] and wild horse advocacy groups frequently question the validity of the population counts.

[7] Nonetheless, each HMA is given an Appropriate Management Level (AML), usually given as a range showing upper and lower limits.

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.

When the 1971 Act was passed, the BLM assessed herd areas to determine which places could become HMAs based on whether they had adequate food, water, cover, and space to "sustain healthy and diverse wild horse and burro populations over the long-term".

[12] There are also some protected free-roaming equine populations found on lands governed by the National Park Service (NPS).

[14] In 1971, free-roaming horses were found on 53.8 million acres of federal land, designated as herd areas.

[14][18] as of March 1, 2014[update] the BLM estimated a total of 49,209 horses and burros were roaming free on BLM-managed lands.

[19] Over half of all the free-roaming horses and burros under the management of the BLM live in Nevada, where there are 83 separate HMAs.

[19] As of 2014[update], 48,447 equines that had been captured, removed from the range were kept in holding facilities in various locations throughout the west and midwest.

Of those remaining in the wild, as of 2016[update], the estimated 67,027 horses and burros are two and a half times the population in 1971 when the Act was passed and about twice the recommended Appropriate Management Level (AML).

Besides removal of about 3,500 animals in 2016 to long-term holding facilities and adoption, the BLM hopes to use fertility control and other tools to reduce numbers of horses on the range.

Third, some HMAs are contiguous and/or jointly administered as a single unit; some of these also may cross state lines,[b] and finally, BLM records vary annually; changing conditions or planned management decisions may remove animals altogether, land swaps and management decisions may transfer land between federal agencies or into private ownership, some areas move from HMA to HA status.