Updated on September 7, 2026. Chronic wasting disease is a fatal prion disease of deer, elk, and moose. It is not a virus, not a bacterium, and not something you can cook out of a steak. As of June 2026 the U.S. Geological Survey has documented it in 37 U.S. states and five Canadian provinces. This page is the map and the hunting playbook. Field signs live on CWD deer symptoms. Drop-off logistics live on how to get your deer tested for CWD.
Parent hub: deer safety. Disease context: deer diseases.
CWD facts (sourced)
| What | Fact | Source |
|---|---|---|
| Cause | Misfolded prion protein (a transmissible spongiform encephalopathy). No vaccine. No treatment. Always fatal in cervids. | CDC, About CWD (Jan. 21, 2026) |
| First recognized | 1967, captive mule deer at a wildlife research facility in northern Colorado. Identified as a TSE in 1978. First free-ranging case: elk, 1981. | USDA APHIS CWD |
| Where it is now | 37 U.S. states and five Canadian provinces in free-ranging and/or captive cervids, plus Norway, Sweden, Finland (wild) and South Korea (captive). Data current as of June 2026. | USGS National Wildlife Health Center map |
| Spread rate | Observed expansion about 14 miles per year from 2005–2022, faster in the West (~9–11 mi/yr) than in the East (~3 mi/yr). | USGS NOROCK, Sept. 2, 2026 |
| People | No documented human CWD infections. CDC still tells hunters in CWD country to test the deer and not eat a positive. | CDC |
| Last checked | September 7, 2026 | USGS June 2026 map; CDC pages dated Jan.–May 2026 |
What CWD actually is
CWD is a prion disease. A normal cellular protein misfolds, then forces neighboring proteins to misfold the same way. Those clumps punch holes in the brain and spinal cord. The animal wastes away — that is the “chronic wasting” in the name — and dies. Related diseases in other species are scrapie in sheep and goats, bovine spongiform encephalopathy (mad cow) in cattle, and Creutzfeldt–Jakob disease in people. Related is not the same as interchangeable. USDA APHIS is explicit: there is no known relationship that lets you treat CWD as BSE with antlers.
Incubation is long. A deer can shed prions in saliva, urine, feces, and blood for months or years while it still looks like a deer. The skinny, drooling, fearless animal in the photographs is end-stage. Most hunter-killed positives look normal. That is why appearance is not a screening tool, and why the symptom list belongs on its own page rather than here.
Search language: “zombie deer disease” is a headline for CWD, not a second illness. If that is the phrase you typed, start at what is zombie deer disease and come back here for the map.
Where CWD is (June 2026)
Do not use a 2020 screenshot. USGS redraws the North American map each year. The June 2026 update is version 4.0 of Chronic Wasting Disease distribution in the United States by state and county. For North Dakota, Wyoming, Idaho, Montana, and Colorado, USGS now plots detections by wildlife management unit instead of county, because that is how those states report.
All 37 U.S. states on the current list have at least one free-ranging detection. Captive-cervid detections are a separate column. Quebec, in Canada, is captive-only. South Korea’s cases are captive, originally tied to elk imported from Saskatchewan.
| State | Free-ranging | Captive |
|---|---|---|
| Alabama | Y | |
| Arkansas | Y | |
| California | Y | |
| Colorado | Y | Y |
| Delaware | Y | |
| Florida | Y | |
| Georgia | Y | |
| Idaho | Y | Y |
| Illinois | Y | Y |
| Indiana | Y | |
| Iowa | Y | Y |
| Kansas | Y | Y |
| Kentucky | Y | Y |
| Louisiana | Y | Y |
| Maryland | Y | |
| Michigan | Y | Y |
| Minnesota | Y | Y |
| Mississippi | Y | Y |
| Missouri | Y | Y |
| Montana | Y | Y |
| Nebraska | Y | Y |
| New Mexico | Y | |
| New York | Y | Y |
| North Carolina | Y | |
| North Dakota | Y | |
| Ohio | Y | Y |
| Oklahoma | Y | Y |
| Pennsylvania | Y | Y |
| South Dakota | Y | Y |
| Tennessee | Y | |
| Texas | Y | Y |
| Utah | Y | Y |
| Virginia | Y | |
| Washington | Y | |
| West Virginia | Y | Y |
| Wisconsin | Y | Y |
| Wyoming | Y |
Canada on the same USGS sheet: Alberta (wild and captive), British Columbia (wild), Manitoba (wild), Quebec (captive only), Saskatchewan (wild and captive). Europe: Norway, Sweden, and Finland in free-ranging reindeer, moose, or red deer. A state on this list is not a statewide infection. Georgia’s 2026 management area is a handful of southern counties. Louisiana’s parish table is still concentrated in Tensas. Colorado has had CWD for decades along the Front Range and plains. Wisconsin’s endemic core is older than a lot of the hunters now sitting in those stands. For the county or unit you actually hunt, use the agency map linked from that state’s hunting guide — Wisconsin, Colorado, and Michigan are three that already spell out zone rules. The 50-state index is deer hunting by state.
How it moves, and why soil matters
Prions leave an infected cervid in saliva, urine, feces, and blood. Direct nose-to-nose contact at a scrape, a mineral lick, or a bait pile is the obvious route. The less obvious route is the ground. Once CWD is established, CDC’s language is blunt: the prions can stay in soil and water for years. Plants growing in contaminated dirt can carry the protein. A carcass dumped in a ditch is not “gone.” That is why so many states now tell you to leave unused parts at the kill site, take them to a landfill, or use an agency dumpster — not a roadside, not a creek, not the back of a public hunting area.
USGS scientists tracking CWD strains have described at least ten distinct prion strains with different biochemical fingerprints. Strain identity affects which hosts get sick and how surveillance labs read a sample. You do not need to know the strain in the field. You do need to know that a “CWD-free county” last November can be a detection county this November, and that live-animal movement — farmed deer, illegally moved bucks, a head in a cooler crossing a state line — jumps the disease farther than a dispersing yearling can walk.
USGS NOROCK’s 2026 movement paper is useful for one reason: deer migration and natal dispersal do not fully explain the observed spread. The disease has been advancing faster than the GPS collars predict, especially in the Canadian prairie. Carcasses, captive facilities, and bait sites are the extra miles.
Which animals get it
Natural hosts are members of the deer family: white-tailed deer, mule deer (including blacktail), elk, moose, reindeer/caribou, sika, and red deer. Species profiles live under deer species. CDC’s animal page is the line to quote for livestock: CWD does not appear to infect cows, other livestock, or pets under natural conditions. Experimental injection can force replication in some lab settings. That is not a pasture outbreak. It is a reason agencies still watch the fence line between a deer farm and a cattle lot.
Farmed cervids are USDA APHIS’s lane. The Herd Certification Program is the federal attempt to keep CWD out of the interstate deer and elk trade. A “certified” herd is not a promise that wild deer on the other side of the fence are clean. If you buy venison from a farm, you are buying under a different inspection system than a wild deer you shot; ask the seller which lab tested the animal.
CWD is not EHD, bluetongue, or mange
Late-summer die-offs along a creek are usually not CWD. Epizootic hemorrhagic disease (EHD) and bluetongue (BTV) are midge-borne viruses. Deer with EHD often run a fever, look swollen in the head or neck, and pile up in water. The outbreak ends with the first hard frost. CWD does not take a winter off. Mange is mites and hair loss. A mangy deer can look terrible and still not have a prion disease. The disease hub that holds the rest of the list is deer diseases.
If you find a dead deer in August, call the agency and say where and when. Do not assume CWD. If you find a walking skeleton in December that has no fear of the truck, treat it as a CWD report until a lab says otherwise.
What a hunter actually does
The CDC hunter list is short on purpose:
- Do not shoot, handle, or eat an animal that looks sick or acts strangely.
- Do not touch or eat meat from an animal you found dead.
- Wear latex or rubber gloves to field-dress.
- Stay off the brain and spinal cord. Do not use kitchen knives.
- In CWD country, have the deer tested before you eat it. Do not eat a positive.
- If a processor batches several deer into one grind, you are eating whoever else was on the table.
That is the human-health floor. State wildlife rules sit on top of it: mandatory vs voluntary sampling, carcass movement, baiting bans inside a management zone, replacement tags for a positive deer. Those rules change when a new county lights up. Read them on the agency CWD page the week you leave, not from memory. The step-by-step for check stations, drop freezers, lymph nodes, and waiting on results is how to get your deer tested for CWD. What the meat looks like — it doesn’t — is what CWD looks like in deer meat. Field-dressing technique is how to field dress a deer, and the rest of the after-the-shot sequence is on after the shot.
Cooking does not kill prions. Freezing does not. Smoking does not. If the lab says positive, the meat is not food. Most agencies will tell you where to dispose of it so those prions do not go back on the landscape.
Can hunting slow it down
You cannot vaccinate a wild herd. You cannot bleach a county. What agencies still have is harvest. A January 2025 USGS and Wyoming Game and Fish analysis of 20 years of Wyoming data found that taking about 40 percent of adult males every year, held for two decades, is expected to keep male infection below about 5 percent. Drop that harvest to 20 percent of adult males and the model lands near 30 percent infected. Some Wyoming mule deer herds have already posted infection rates above 50 percent. That is not a bag-limit argument from a gear company. It is the federal wildlife lab saying that consistent, heavy buck harvest is one of the few tools that has a number attached.
Agencies also ban baiting in some CWD zones, restrict moving live deer, and pay for hunter samples because those samples are the surveillance network. If you hunt a new detection county and skip the drop freezer, you are the hole in the map.
People, venison, and what has not happened
CDC’s current line, dated January 21, 2026: CWD infections in people have never been reported, and it is not known whether people could get infected. The caution exists because BSE did jump to people as variant Creutzfeldt–Jakob disease, and because some macaque studies showed infection after the animals were fed CWD-positive meat or brain. A CDC survey of U.S. residents found nearly 1 in 5 had hunted deer or elk and more than 6 in 10 had eaten venison or elk. Those are the people who would be first in line if a jump ever showed up.
That is why the recommendation is a cheap hedge: test in CWD country, bone the meat, skip the backstrap that sat against the spine if you are queasy, and do not eat a positive. CDC is also surveying hunter health in long-endemic states so a human signal would not have to wait for a newspaper. None of that is the same as “CWD has infected people.” It has not, on the evidence published through 2026.
FAQ
Is CWD in my state?
If your state is in the USGS table above, yes — somewhere. That is not the same as “every county.” Pull the current agency map. New detections land every season. USGS and CDC both say the disease is expected to keep spreading, and that it may already be in places that have not sampled enough to find it.
Can I tell CWD by looking at the deer or the meat?
No. Clinical signs show up late; most positives look healthy. The meat looks like meat. Use the lab. Details: symptoms and meat.
Does CWD affect the whole deer population?
Nationwide prevalence in free-ranging deer is still low. In long-endemic pockets it is not. Wyoming mule deer herds over 50 percent infected are a real number from the USGS hunting study, not a rumor. High prevalence plus a 100 percent fatal disease is how a herd shrinks even when the habitat looks fine.
Should I stop hunting?
No. Testing, carcass rules, and not shooting sick animals are the control points. In some herds, hunting pressure is the management. Sit out of spite and the model gets worse, not better.
Official sources
- USGS: Expanding distribution of CWD (map and state table, updated June 30, 2026)
- USGS data release: CWD distribution by state and county, ver. 4.0, August 2026 (data current through June 2026)
- CDC: About CWD
- CDC: Where CWD occurs
- CDC: CWD in animals
- USGS: hunting as CWD control (Jan. 27, 2025)
- USGS NOROCK: spread rate and deer movement (Sept. 2, 2026)
- USDA APHIS: CWD control and eradication
Related on WorldDeer: safety hub · deer diseases · CWD symptoms · zombie deer disease · CWD in meat · CWD testing · EHD · mange · hunt by state.
