WASHINGTON - Tempers flared at a congressional hearing Tuesday over the management of bison in Yellowstone National Park, with solutions ranging from stopping the animal's slaughter to allowing them to be hunted within the park.

House Natural Resources Committee Chairman Nick Rahall, D-W.Va., asked why the Interior Department is "murdering its beloved mascot."

"The slaughter of bison is not required in order to manage the threat of disease," Rahall said. "Slaughter is not management."

Rahall said his narrowly defeated effort in 2003 to halt the National Park Service's participation in the slaughter was a "harbinger of what will come."

But Montana Gov. Brian Schweitzer and Rep. Denny Rehberg, R-Mont., said stopping the slaughter would have dire consequences. They offered other solutions for managing the bison herd, while federal officials defended the current plan.

The dispute centers on the potential for bison that wander out of the park in winter to spread a disease called brucellosis to cattle. Schweitzer said the current management plan, approved by five federal and state agencies in 2000, ensures that it's only a matter of time before Montana will lose its brucellosis-free status. That would cost hundreds of millions of dollars per year for the cattle industry, he said.

One possible solution would be more active management of bison in the park, Schweitzer said, such as attempting to eradicate the disease. That would mean testing all the bison in the park for brucellosis, slaughtering those that test positive, and vaccinating the rest. But he acknowledged that likely there will not be willingness to do so and that elk also carry brucellosis.

Schweitzer said another permanent solution would be for Congress to pay private landowners in a small area north and west of the park where bison migrate in winter to keep cattle and sheep off the land. They would be allowed to raise horses and mules on the land.

A third option would be to have a buffer zone 30 to 50 miles north of the park in which 100 percent of the cattle that enter and leave the space are tested for brucellosis, Schweitzer said. In exchange, the federal government would agree that Montana would not lose its brucellosis-free status should the current limit of two herds become infected inside the designated area.

Schweitzer noted that Montana has established a bison hunt in recent years and argued that bison should be allowed to be hunted inside the park.

"We ought to be able to hunt them on the other side of the line," he said. "I don't know why the federal government can't follow the lead of Montana."

Rehberg testified that Rahall was wrong about ending slaughter. He said the 2000 agreement was a complex management compromise and that the secretaries of Interior and Agriculture and the governor of Montana all agreed to it.

Rehberg said bison will continue to reproduce until ultimately there will be too many. "You're not going to end the slaughter for practical reasons, for natural reasons," he said. He said the management plan also protected health, livestock and private property rights.

"I've got an answer: Why don't you fix your herd?" Rehberg said. He said the park is poorly managed as far as grazing and that the first option should be to herd the bison as with livestock, rather than buying private property or grazing rights on lands outside the park.

But John Clifford, deputy administrator of the Animal and Plant Health Inspection Service, said cooperative efforts to battle brucellosis have been successful. He said the 2000 plan carefully balances preserving the herd with preventing the spread of brucellosis.

He said the next step will be developing a long-term plan of eliminating the disease from the greater Yellowstone area. He said the agency is in the early stages of formulating such a plan, and will be seeking both expert and public input. As for establishing a buffer zone, Clifford said he saw no point in changing the plan that's "been so effective for so many years."

Schweitzer disagreed on its effectiveness, noting that Wyoming and Idaho had lost their disease-free status in recent years. Wyoming did regain its status last year.

Rahall noted there has been no documented case in the wild of bison transferring the disease to cattle. But Clifford said captive bison being raised commercially have given the disease to cattle.

At Rahall's request, the Government Accountability Office is putting together a report on the progress made under the 2000 plan. Robin Nazzaro, director of natural resources and environment at the GAO, said a preliminary review found that the agencies that agreed to the three-step plan remain on step one.

They cannot move forward until an agreement is reached with landowners to keep cattle from grazing in the winter on certain lands north and west of the park.

Schweitzer said the state is negotiating with the Royal Teton Ranch, owned by the Church Universal and Triumphant, to compensate it to keep sheep and cattle out of the space. He said most real estate negotiations have six or eight rejections before a deal is cut, and said the state is probably on its fourth or fifth "no" before it gets a "yes."

Yellowstone Superintendent Suzanne Lewis said the bison leave the park not because it is overgrazed but because during harsh winters they are in search of areas with less snow. National Park Service Associate Director Mike Soukup said the bison are "nowhere near capacity" and that the park could hold 7,500 bison.

But Schweitzer said with the current 3,600 bison, the park is grazed more than most of the ranches in Montana. "The more bison we have, the more likely they are to leave," he said.

Asked which the Park Service valued more, Soukup said that maintaining a free-roaming herd in the park is a higher priority than working to make the herd brucellosis-free. Rep. Rob Bishop, R-Utah, said the Park Service was "deeply wrong" if making the herd disease-free isn't its highest priority.

Lewis said the park did not capture any bison this year, but there were about "500 events" of hazing to chase about 150 bison nearing the north border back into the park. She said most of the bison herd does not move in the winter.

Josh Osher of the Buffalo Field Campaign said that group does not support continuation of the current plan. He said killing all bison in the park that test positive for brucellosis would be a "sledgehammer" approach and not an appropriate management tool. But the group would support zone management or buying out grazing rights, he said.