Although it has not yet been detected in the park, Chronic Wasting Disease poses a threat to Glacier’s elk population.
Photo: NPS
One of the most unique experiences in Glacier National Park is the chance to view an intact ecosystem full of wild and untamed animals. Glacier’s majestic megafauna are a special resource that we can never take for granted, and an intact ecosystem is not something that merely happens—it requires the tireless work of park biologists to protect the habitat and safety of these creatures. One of the biggest threats facing Glacier’s animals today is the specter of invasive disease.
Disease management requires rigorous monitoring, to identify and sequester outbreaks as quickly as possible. With your support, the Glacier Conservancy is proud to fund wildlife disease monitoring in Glacier National Park. Leading the charge in this monitoring effort is Glacier’s Natural Resource Program Manager, Mark Biel.
In over a dozen years working in Glacier, Mark has noticed big changes in the threat posed by emergent wildlife disease, “Five years ago, wildlife health monitoring wasn’t really that big of a topic. But as the climate is changing, it’s making this area more conducive to diseases and pathogens that previously wouldn’t have been able to survive in Glacier.”

Moose are also threatened by CWD. Photo: Debbie Leff
Among the most serious of these diseases is Chronic Wasting Disease (CWD). CWD is a prion disease, like Mad Cow Disease in cattle or Creutzfeldt-Jakob Disease in humans. This disease is caused by abnormal proteins called prions and is induced in animals when normal proteins turn into prions, which causes brain cells to die. It affects members of the deer family—including whitetail deer, mule deer, elk, and moose. CWD is highly transmissible and always fatal—there is no known treatment.
Although CWD has not yet been detected within the boundaries of Glacier National Park, the threat of it is very real. “I came up with this project because in late 2020 we were notified that there was a wild game farm in Flathead County that had an animal test positive for chronic wasting disease,” Mark says, “we were later notified by the Blackfeet Fish and Wildlife Division of a deer that had been harvested on the reservation and tested positive for CWD. That was less than 20 miles from the park boundary.”
There is currently no accurate test for CWD in live animals, so Mark and his team collect samples from deer, elk, and moose that are found dead—primarily from road kill. Both retropharyngeal lymph nodes are removed from the animal and sent to a lab for testing.

Deer with CWD have been detected near Glacier National Park. Photo: NPS
This project emphasizes cooperation—the only way to manage CWD is along with Glacier’s neighbors. “Wildlife don’t know what the lines on the map mean—they go up to Canada, over to the Blackfeet Nation, onto National Forest, or state, or private lands,” Mark adds, “part of this project is working with Montana FWP and the Blackfeet Nation to make a plan to notify each other when cases come up and committing to work collaboratively on this issue.”
The project includes monitoring efforts for other diseases, including rabbit hemorrhagic disease and highly pathogenic avian influenza.
Rabbit hemorrhagic disease has not yet been detected in Glacier, but monitoring is critical because the disease is highly contagious and nearly always lethal. This viral disease could affect any of the lagomorphs (rabbit family) in the park including the mountain cottontail, white-tailed jackrabbit, snowshoe hare, and one of Glacier’s most popular animals, the American pika.

Rabbit hemorrhagic disease is nearly always lethal in pika. Photo: GNPC
Similar to the CWD monitoring, Mark’s team will opportunistically test any animals found dead. Fortunately, so far, the only rabbit family animals found have been road kill, which have a known cause of death.
The safety of Glacier’s wildlife from emergent disease is a key factor in the continued health of the park ecosystem. This project allows park biologists to have the data they need to handle disease outbreaks as they happen. With your support, and the work of people like Mark Biel, future generations of park visitors will have a chance to see wild deer, elk, moose, and pika in Glacier, just like we can today.
Your Support Makes A Difference
This project and many other critical projects would not be possible without your donations to the Glacier Conservancy.
Give now to make projects like this possible in Glacier National Park!