If the disease prevalence is higher than 5 percent of the deer population, the state will step up its efforts to find and remove infected deer. “That could be increasing the harvest of bucks because bucks are two to three times more likely to be infected and to spread the infection,” Mr. Vore said. “If there are hot spots within the broader area with high prevalence, we can go in and address deer density in those hot spots. If we have large aggregations of deer in an alfalfa field, for example, we want to address that.”
If it’s under 5 percent, officials will continue to monitor hunters the way they are now and not do more aggressive culling.
Hunters here are concerned, but waiting to see what happens. “Between deer and elk, all I eat is wild game,” said Brodie McDonald, an electrician in Laurel, Mont., who brought his white tail buck in the back of a truck here to be tested. “If it comes back positive I won’t eat it, but if it’s negative I will,” Mr. McDonald said. “It worries me that it might become more widespread and you have to get every deer you shoot tested.”
The lymph nodes taken from the check station are tested at a lab in Fort Collins, Colo. Ms. Goosman said hunters are notified if positive tests are confirmed, and should throw out the meat.
And those who hunt in areas where the disease is known to occur should bone out their meat and not consume the brain, spine or lymph nodes, experts said.
Though chronic wasting disease has not been detected in the vast herds of elk, or in deer and moose in Yellowstone, officials are worried it will find its way into the park and diminish the size of the herds.
Wyoming has had infected deer and elk since 1985, the disease now present in 21 of 23 counties. Experts say mule deer can decline by as much as 20 percent a year and localized extinction of some herds is possible.
Mr. Vore said Montana will move aggressively to eradicate the disease by culling deer. “In some states it has decreased animal populations by 40 percent,” he said. “We want elk and deer to be around for our kids and grandkids for everybody to enjoy 20 and 30 years from now.”
New York is the only state that has apparently been able to eliminate the disease through the culling of infected populations when first detected.
Many states without the disease ban hunters from bringing in parts of the carcasses of deer they have killed in states with existing infections.
Wyoming has become a center of concern for many biologists, who warn that the way that it manages its elk herds could exacerbate the spread of the disease should the infections turn up in feeding grounds.
There are 22 state elk feed grounds and one federal feed ground, the National Elk Refuge, next to Jackson, Wyo., that feed elk in the winter to keep them eating hay on ranches. The feeding concentrates the animals by the hundreds and thousands, a recipe for magnifying the incidence of disease, and spreading it, biologists say. The prions are believed passed through waste and saliva.
In a letter to Keith Culver, president of the Wyoming Game and Fish Commission, Dan Vermillion, chairman of Montana’s Fish & Wildlife Commission, requested an end to the controversial practice. If not “we will all be culpable in leaving a greatly devalued landscape to future generations,” Mr. Vermillion wrote. “As your neighbor, we ask you to begin the process of closing these feed grounds.”
Mr. Culver said the state had no plans to close the grounds. “We continue to look at ways to improve management of feed grounds,” he said, noting that the disease has never been found in them and even if it were, it might not exacerbate the infection rates. “Elk are a herd animal and tend to congregate anyway.”