Wild horses from the Onaqui Herd near Dugway, Utah. © BLM
Salazar's plan for the future management of US wild horses would entail acquiring more productive grasslands on which to manage the herds.
Citing limits on forage and water in the West because of persistent drought and wildfire, Salazar said the lands acquired by the Bureau of Land Management and/or its partners "would provide excellent opportunities to celebrate the historic significance of wild horses, showcase these animals to the American public, and serve as natural assets that support local tourism and economic activity".
Salazar said the wild horse herds placed in these preserves would be non-reproducing.
Wild horse advocates have long been critical of the bureau's management of populations on the western rangelands.
Ongoing musters and a fall-off in adoptions has seen the number of horses held in captivity nearly match the 33,000 estimated to still roam free on the Western rangelands.
Salazar is seeking Congressional support for what he calls a sustainable national programme to manage the horses, aimed at restoring the health of America's wild horse herds and the rangelands.
Interior Secretary Ken Salazar
"The current path of the wild horse and burro programme is not sustainable for the animals, the environment, or the taxpayer," Salazar said in a letter outlining his proposals to Senate Majority Leader Harry Reid and eight other key members of Congress with jurisdiction over wild horse issues.
Salazar said he is "proposing to develop new approaches that will require bold efforts from the Administration and from Congress to put this programme on a more sustainable track, enhance the conservation for this iconic animal, and provide better value for the taxpayer."
Bureau of Land Management director Bob Abbey commended Salazae for his initiative, saying: "The proposals we are unveiling today represent a forward-looking, responsive effort to deal with the myriad challenges facing our agency's wild horse and burro programme."
Abbey continued: "We owe wild horses and burros on Western rangelands high-quality habitat. We owe the unadopted wild horses and burros in holding good care and treatment. And we owe the American taxpayer a well-run, cost-effective wild horse programme.
"Today's package of proposals will achieve those ends."
The challenges to the bureau associated with maintaining robust wild horse populations in the West have been recognised by the Senate Appropriations Committee, which has warned that gathering and holding costs have risen beyond sustainable levels. It directed the bureau to prepare a long-term plan for the programme.
The Government Accountability Office also found the programme to be at a "critical crossroads", affirming the need to control off-the-range holding costs. It recommended that the bureau work with Congress to find a responsible way to manage the increasing number of unadopted horses.
In response to the Congressional direction, Salazar's proposals aimed to achieve what he called a "truly national solution" to a traditionally Western issue.
In four decades under the bureau's protection, wild horses that were fast disappearing from the American scene have returned to rapid growth.
"As wild horses have no natural predators and herds grow quickly," Salazar said in his letter, "more than 33,000 wild horses live in 10 western states.
"Unfortunately, arid western lands and watersheds cannot support a population this large without significant damage to the environment."
The bureau works to achieve an ecological balance on the range by removing thousands of wild horses and burros from public rangelands each year and then offering them for adoption.
"Unadopted animals are cared for in short-term corrals and long-term pastures. With the sharp decline in wild horse adoptions in recent years because of the economic downturn, the bureau now maintains nearly 32,000 wild horses and burros in holding, including more than 9500 in expensive short-term corrals."
In the 2008 fiscal year, the cost of holding and caring for these animals exceeded $US27 million - three-quarters of the $US36.2 million budgeted for the entire wild horse and burro programme that year.
In the most recent fiscal year (2009), which ended September 30, holding costs were about $US29 million, or about 70 per cent of the total 2009 enacted wild horse and burro programme budget of $US40.6 million.
A key element of the Secretary's plan involves new wild horse preservation areas across the US, using more productive grassland than the arid West.
Salazar also proposes: