Yellowstone is the nation's last reservoir of brucellosis, a disease prevalent in wild bison and elk that is sometimes passed to livestock. It can cause pregnant animals to miscarry.
To prevent the disease from re-infecting livestock herds in other parts of the country, the U.S. Department of Agriculture wants to make parts of Montana, Idaho and Wyoming a "National Brucellosis Elimination Zone."
Cattle producers in counties surrounding Yellowstone National Park would face increased restrictions when exporting their animals. That includes requirements for routine vaccinations and disease testing, now required only when brucellosis infections occur.
But Gov. Dave Freudenthal of Wyoming and Gov. Butch Otter of Idaho are asking U.S. Agriculture Secretary Tom Vilsack to withhold action on the proposal.
The governors wrote in a Tuesday letter to Vilsack that the "hastily contrived" plan would allow the government to "walk away from the issue forever", without getting rid of the disease.
"Brucellosis, in a national and even regional sense, will simply fade from the public conscience with the states of Wyoming, Idaho and Montana being left to their own devices to deal with yet another unfunded federal mandate," the governors wrote.
They added that the federal plan does little to address the disease in wildlife, opening the possibility of repeated infections among Yellowstone-area cattle ranches.
Gov. Brian Schweitzer of Montana was not asked to sign onto the letter because the state veterinarian there has not opposed the federal plan, Freudenthal spokeswoman Cara Eastwood said.
Livestock groups in Wyoming and Idaho had pressured the state's elected officials to oppose the federal plan.
Tom McDonnell, vice president of the Idaho Cattle Association, said the zone would give the region "a black eye."
"It does absolutely nothing to eliminate brucellosis unless they eliminate it in the wildlife," he said.
Sixty-eight Idaho ranches with 8,500 cow-calf pairs would be included in the federal zone, McDonnell said. Figures for Montana and Wyoming were not immediately available.
Veterinarians from states outside the region also have weighed in against the federal proposal. They, too, want more attention paid to brucellosis in wildlife.
The federal government last year laid out an ambitious timeline to put the new brucellosis zone in place. That schedule was abandoned after opposition to the plan began to build.
Federal officials decided to solicit more public comment on the idea before putting it into place.
"The ideas and comments we get will help us set a new timeline," said Lyndsay Cole, a spokeswoman for the Animal and Plant Health Inspection Service, the Department of Agriculture branch that oversees brucellosis control efforts.
"The concept is intended to spur conversation on what people think will and will not work within their states," she added.