WASHINGTON -- Thousands of mustangs that now roam the West would be moved to preserves in the Midwest and East under a new Interior Department plan to protect wild horse herds and the rangelands that support them.

Interior Secretary Ken Salazar said Wednesday the plan would not require killing any wild horses. Interior Department officials had warned in recent months that slaughtering some of the 69,000 wild horses and burros under federal control might be necessary to combat rising costs of maintaining them.

Nearly 37,000 wild horses and burros roam in Nevada, California, Wyoming and other Western states, and another 32,000 horses and burros are cared for in corrals and pastures in Kansas, Oklahoma and South Dakota.

Salazar said the current program is not sustainable for the animals, the environment or taxpayers.

The wild horse program, run by the Bureau of Land Management, cost about $50 million this year, officials said, up from $36 million last year. Costs for the current program are expected to rise to at least $85 million by 2012.

The bureau rounds up thousands of the animals annually but has had a hard time finding buyers in recent years.

In a conference call with reporters, Salazar and bureau director Bob Abbey urged Congress to authorize seven wild horse preserves -- including two owned and operated by the BLM. The agency would work with private groups on the remaining reserves, which would be located in states in the Midwest and East.

Water and forage are extremely limited in the West, Salazar said, and drought and wildfires threaten both rangeland and animal health in many Western states. "Unfortunately, arid Western lands and watersheds cannot support a population this large without significant damage to the environment," he said.

Salazar did not identify where the preserves would be located, but said the two federally owned preserves would cost about $92 million to buy and build. The preserves would reduce taxpayer costs for care of wild horses in the long term, Salazar said.

"It also will be better for the horses," he said.

The seven preserves would hold about 25,000 horses. Many of the horses remaining on the range would be neutered, and reproduction in Western herds would be strictly limited, Salazar said.

Some ranchers, American Indian groups and Western lawmakers have proposed reversing a decades-old ban on selling wild horses for slaughter, but Salazar, a former rancher, called that idea a nonstarter.

"The fact is that the American public has shown that it does not want to have slaughtering of these animals," he said.

Rep. Nick Rahall, D-W.Va., chairman of the House Natural Resources Committee, welcomed Salazar's plan, which he said would reverse decades of government policies that treated wild horses and burros as a nuisance.

"Years of attempts by BLM to shoehorn these magnificent animals into ever-shrinking territory has manufactured an overcrowding problem," Rahall said. "Restoring horses and burros to the acreage from which they have been needlessly removed is critical."

Spokesman Tom Gorey said the land management agency would work with state and local officials to create the preserves -- essentially large ranches -- and make them accessible to the public.

"We think there is real potential for ecotourism," he said. "Everybody loves horses."

Wild horses in Wyoming

* Numbers: About 4,500 wild horses are scattered across 16 herd management areas in Wyoming, most in the southwest. The Bureau of Land Management has a statewide objective of from 2,700 to 3,700 of the animals, according to agency officials.

* Roundups: Federal officials say wild horses have no natural predators, and with an annual reproduction rate of between 15 to 20 percent, the excess animals must be periodically removed from public rangelands to achieve population objectives. Several such roundups have been conducted or are in planning now.

* Corrals: Wild horses that are captured during roundups in Wyoming are taken to the BLM's holding facilities in Rock Springs, with capacity for 600 animals.

* Training for adoption: The BLM has agreements with the Wyoming Honor Farm in Riverton, where wild horses are trained by inmates, and with the Mantle Ranch near Wheatland, where wild horses are also gentled and trained for adoption.

* State mandate: In 2003, after wild horse populations in Wyoming soared upwards of 7,000 animals, the state and the BLM signed a "consent decree" dictating that the agency meet the state's wild horse objective number with roundups.

On the Web:

BLM wild horse and burro program: http://tinyurl.com/3rb6r7