Wyoming Mule Deer See CWD Spreading: Report
Zac K. 04.10.25
Wyoming’s mule deer population is seeing chronic wasting disease (CWD) increase its prevalence throughout the state, according to research undertaken through 2024.
The Wyoming Game and Fish Department’s Wildlife Health Laboratory released its 2024 CWD Surveillance Report in the past few weeks. The results are not what hunters and other conservationists might have hoped for, although it wasn’t all bad news. According to the samples studied last year, mule deer saw an increase, although it wasn’t a large one. On the other hand, whitetail deer and elk both saw a decline in CWD percentage, and none of the moose samples tested positive.
Samples tested from mule deer, white-tailed deer, elk and moose included hunter-harvest, targeted and road-killed animals. Of those samples tested, 19.4% came back positive in hunter-harvested mule deer bucks, 29.2% in hunter-harvested white-tailed bucks and 2.3% in adult, hunter-harvested elk. The percentage of mule deer bucks increased from 2023 at 18.9%. The percentages for white-tailed deer and elk decreased from 2023 at 30.3% and 2.8,% respectively. There were no positive CWD samples from moose.
The Fish and Game authorities said they tested 5,276 samples in 2024, up from 5,100 samples in 2023. There is no charge for hunters to have their game tested for the presence of CWD.
Deer Hunt Areas 31, 53, and 94 were also newly confirmed to have CWD-positive animals.
At this point, the Lander Region’s Project Herd has the highest CWD percentage among whitetail populations, measured to be 66.3 percent, with the Shoshone River herd in the Cody Region in second place at 47.6 percent. In southeast Wyoming, the Iron Mountain herd has the highest percentage of CWD-positive elk, estimated at 10.1 percent, and the North Bighorn herd in north-central Wyoming has jumped to 9.1 percent from its 7 percent prevalence over 2019-2024.
Take note that even these numbers do not necessarily apply to the herd across the whole region. The wildlife authorities explain their formula this way:
To determine CWD prevalence in individual herds, five-year averages were calculated to ensure a significant sample size … Prevalence calculated at the herd until level provides managers with perspective on herd unit health and can direct herd level management actions. However, CWD levels are not uniform across a herd and can accumulate in hot spots of higher concentration within these herd units.
But it’s still a grim thing. Last year, Wyoming’s wildlife experts believed 95 percent of the state’s mule deer hunting areas and 62 percent of the elk hunting areas were endemic for CWD. It’s spreading to all deer populations everywhere, slowly—except for moose, it seems.
How you can help fight CWD
To help authorities try to manage the problem, the Game and Fish department says CWD sampling is important for early detection, so they can figure out strategies to deal with the issue before it becomes dangerous to the herd. That’s where outdoors enthusiasts can play an important part.
“Wyoming’s CWD surveillance would not be possible without the participation of our hunters,” said Jessica Jennings, manager of the Game and Fish Wildlife Health Lab. “We encourage hunters to check the Game and Fish website for the 2025 priority and mandatory testing areas, check current CWD prevalence on the interactive CWD map, and no matter where you hunt, please consider having your animal tested for CWD.”
Find more information on Wyoming’s CWD programs here.
