Yellowstone National Park officials are issuing a warning to travelers, urging them to avoid wildlife encounters, as a “zombie” deer infected with chronic wasting disease (CWD) was discovered near Yellowstone Lake. The deceased adult mule deer displayed symptoms typical of CWD, including excessive drooling, drooping ears, head tremors, teeth grinding, and reluctance to move. The disease, which is contagious and fatal, affects deer, reindeer, elk, and moose.

The deer, previously tagged by the state’s Game and Fish Department in March and tracked by its GPS collar, died in October. Samples collected from the carcass tested positive for CWD at the Wildlife Health Laboratory. Although CWD has been detected in various regions globally, including 31 US states, two Canadian provinces, South Korea, and Europe, this marks the first recorded instance within Yellowstone National Park.

CWD has been spreading in Wyoming since the ’80s, infecting 10 to 15 percent of mule deer in the state. Animals can contract the disease through direct contact or indirectly through an infected environment. The incubation period for symptoms can exceed a year, and some animals may die without showing overt signs of the disease.

While there is currently no evidence that CWD can infect humans or domestic animals, officials emphasize the uncertainty of its long-term impact on deer, elk, and moose in the Yellowstone area. Despite this, cautionary measures include not allowing infected meat to enter the food chain. Yellowstone National Park authorities plan to intensify testing and monitoring efforts in response to the presence of CWD.