Chronic Wasting Disease (CWD) has been detected in four new hunting districts since July 2025, according to the Montana Department of Fish, Wildlife and Parks (FWP). These districts are located in regions 3, 4, and 6, covering the southwest, north-central, and northeast areas of the state. The department reported 433 positive CWD tests out of 8,574 conducted since July, marking an increase from the previous year. However, FWP stated it is too soon to determine any new trends.
“Without this data, the risk of CWD going undetected increases, which can lead to significant, long-term declines in herd health and hunting opportunities,” an FWP release emphasized. The proactive management approach relies on hunter-submitted data to ensure the resilience of Montana’s big game populations.
Among the positive results, 250 were white-tailed deer, 179 were mule deer, and four were elk. Last year, there were 356 positive tests from nearly 10,000 samples, as noted in the 2024 CWD report. The report highlighted that testing focused on areas with known high concentrations of CWD.
Biologists use this data to track disease spread and inform management actions, such as extending hunting seasons or focusing sampling efforts. Jacobsen stated, “We use the proportion of positive CWD tests from adult hunter-harvested animals to calculate prevalence in each hunting district.” The data from the past three years and new detections are considered for these calculations.
Between July and now, FWP processed 8,574 samples, with 433 positive results. The week of November 13-19 had the highest sampling, with 1,741 samples collected. Samples included 4,537 white-tailed deer, 3,047 mule deer, 944 elk, and 46 moose. FWP is not ready to report on disease prevalence compared to last year, pending data cleanup. Some hunts are still active, which may also affect the data.
“We would like to thank our hunters and local communities for your collaboration with our seasonal CWD staff,” said Sam Treece, FWP’s wildlife CWD technician supervisor, in a press release. Hunters received test results in an average of 7.6 days.
CWD is a fatal neurological disease affecting elk, deer, and moose. It is a transmissible spongiform encephalopathy caused by prions, spread through contact with bodily fluids or contaminated soil. No cure exists, and while it has not been transmitted to humans, meat from infected animals should not be consumed.
Testing options include mailing lymph nodes or bringing the animal’s head to FWP offices. Results are available online. Around 30% of Montana hunting districts have CWD-positive animals, with the state tracking the disease for nearly three decades.
Extended Hunting Season
FWP announced an extended season for white-tail deer hunting in southwestern Montana due to increased CWD cases. This extension, until February 15, 2026, applies to all of Hunting District 309 and parts of HDs 301, 304, 311, and 312, primarily along the Gallatin River corridor. The goal is to reduce white-tailed deer population density.
Hunters are reminded to check CWD hunt boundaries and follow weapon restrictions in Hunting District 309. “Reducing deer numbers in key areas is one of the most effective tools we have to slow the spread of CWD,” stated Warren Hansen, Region 3 wildlife manager.
