WASHINGTON - A House committee has passed legislation that would prohibit the killing of healthy wild horses and burros to control their populations on federally managed lands.

About 33,000 wild horses and burros roam in 10 Western states, more than half of them in Nevada. About 3,600 wild horses live in Wyoming.

Officials with the Bureau of Land Management say that the number of horses and burros exceeds what's healthy for the land they live on as well as for the animals. They said last summer that one option for controlling the population was euthanasia.

Lawmakers responded with legislation that would make more range land available to wild horses. The bill that passed the House Committee on Natural Resources also would bolster an adoption program and increase the use of sterilization.

It's uncertain when the full House will take up the bill and if the Senate will consider such a measure.

A recent Government Accountability Office report said the BLM this year will spend about $27 million caring for the animals. Continuing current practices would require a budget of $58 million next year, escalating to $77 million in 2012.

The report also noted that euthanasia, though unpalatable, is authorized under current law as a way to dispose of excess animals.

U.S. Rep. Cynthia Lummis, R-Wyo., is a member of the House Natural Resources Committee. She released a statement Wednesday criticizing the wild horse bill. She said she added two amendments intended to improve the measure.

"Careful and balanced management of the rangeland is the only way to ensure our ranges remain a healthy habitat for native plants, wildlife, livestock and wild horses," Lummis said in a prepared statement. "Unfortunately, (this bill), as it is currently written, fails to live up to that careful and balanced approach."

Lummis' first amendment would specify that any proposed expansion of rangelands for wild horses be studied to determine the impacts on rangeland health, riparian zones, water quality, soil compaction, native wildlife, and endangered or threatened species.

Lummis' second amendment would allow the removal of horses if the health of native plant or wildlife species is threatened, her office said in a news release.