In 1971, wild horses and burros were found roaming across 53.8 million acres of Herd Areas (HAs), of which 42.4 million acres were under the BLM's jurisdiction. Today the BLM manages wild horses and burros in subsets of these HAs, known as Herd Management Areas (HMAs) that comprise 31.6 million acres, of which 26.9 million acres are under BLM management.
After an initial Appropriate Management Level (AML) of 32 was established in 1980, improved conditions within the Bordo Atravesado allotment allowed the BLM to increase the AML to 50 in 1989. In 1992, 13 horses from an unrelated herd were introduced in order to improve genetic diversity. In 1997 and 1998, two stallions were introduced for the same purpose. BLM installed a solar water pump in 2007 to ensure steady water availability. A vegetation treatment was performed in 2002 in order to enhance forage and improve the watershed.