South Dakota's EHD Outbreak Is Reshaping the 2026 Deer Season — And Hunters Are Feeling Every Bit of It
It was supposed to be a fall like any other across the Missouri River corridor — crisp mornings, golden river bottoms, whitetails fattening up ahead of the rut. Instead, South Dakota hunters are watching one of the region's most consequential wildlife disease outbreaks in recent memory unfold in real time, and the state's Game, Fish and Parks Department is making unprecedented mid-season moves to protect the herd. License refunds, removed tags, and sweeping regulation changes have scrambled the 2026 deer season before firearm hunters have even hit the woods.
Reports of deer deaths from a viral disease have spiked as hunters take to the fields in South Dakota, and state wildlife officials are reducing some hunting opportunities and offering hunting-license refunds to protect deer numbers. The culprit is epizootic hemorrhagic disease — a name most serious Great Plains hunters know well, though an outbreak of this scale is forcing even veteran outdoorsmen to rethink their plans.
What Is Epizootic Hemorrhagic Disease?
Epizootic hemorrhagic disease is a viral illness spread by tiny biting midges typically found along muddy shorelines. The disease is caused by an orbivirus — the same viral genus responsible for bluetongue disease — and it attacks the vascular system of its host, causing internal bleeding and tissue damage that can progress rapidly from infection to death. EHD is a hemorrhagic disease of white-tailed deer caused by an infection of a virus from the genus Orbivirus. It is an infectious, and sometimes fatal, virus characterized by extensive hemorrhages, and is found throughout the United States.
Infected animals may develop fever, swelling around the head and neck, and other symptoms. Some deer may be found near water as they attempt to cool themselves, while others can die from the disease. The behavior of seeking water is one of the hallmark signs that field observers — hunters, landowners, and wildlife managers alike — use to flag suspected cases. A deer standing in a stock pond or creek in mid-October is a red flag, not a curiosity.
Hemorrhagic disease is caused by either epizootic hemorrhagic disease (EHD) or bluetongue virus. Both are spread by biting midges and can cause serious illness or death in deer. Some infected deer may show few symptoms, while others can develop fever, tongue swelling and respiratory problems. That clinical variability makes the disease particularly difficult to track from the ground. A landowner might observe a deer stumbling near a creek and think little of it; by the time the animal is found dead days later, the midge responsible has already moved on to the next host.
Who Is at Risk
In South Dakota, the disease primarily impacts white-tailed deer, according to Game, Fish and Parks Senior Wildlife Biologist Byron Buckley. Buckley, who presented updated outbreak data to the commission in Pierre earlier this month, explained why whitetails bear the brunt of EHD in the state: "Because white-tailed deer generally inhabit the areas where these midges currently are," he told the Game, Fish and Parks Commission on Thursday in Pierre. Put simply, the geography of the insect matches the geography of the species most vulnerable to it.
Mule deer, bighorn sheep, elk and pronghorn can also be infected. For hunters chasing mulies in the breaks of the Black Hills or pursuing pronghorn across the open gumbo flats, that's not an idle concern. Mule deer, bighorn sheep, elk and pronghorn, which can also suffer from EHD, ordinarily don't live in the northeastern parts of South Dakota — which explains why the northeastern corner of the state has, so far, been spared the worst of the 2026 outbreak. The disease has concentrated itself where the habitat, the insects, and the whitetails converge: the Missouri River corridor and the southeastern river counties.
The Numbers Behind the 2026 Outbreak
The scale of the current outbreak has grown dramatically since summer. Game, Fish and Parks says more than 400 deer deaths have been reported this year, more than double the total reported just a month ago. That acceleration is striking. During the commission's monthly meeting, Buckley said the department now has about 407 reports this year of dead deer due to the illness — 376 suspected cases and 31 lab-confirmed. During the commission's Sept. 10-11 meeting, the count was 196. In other words, as much as half of the year's entire reported mortality happened within the span of roughly a month — precisely the window when hunters started filing into the field.
Buckley acknowledged the complication that hunting season itself introduces into disease surveillance. "So a lot of our reports have come from the month of October," Buckley said. "Now, that could be because we are seeing the disease a lot more or that there's just a lot more people on the landscape." It's a classic signal-versus-noise problem in wildlife disease monitoring: more eyes on the ground means more reports, but not necessarily a proportional increase in actual mortality. Still, the raw numbers are hard to dismiss.
The number of reported cases for 2026 is slightly higher than the total reported for all of 2025, according to the state's EHD map, though Buckley described this year's numbers as roughly comparable to the previous two years. That context matters. South Dakota has contended with EHD on and off for decades, and a single bad year doesn't automatically translate into long-term herd collapse. But consecutive years of elevated mortality — layered on top of a brutal winter, spring flooding, and persistent drought stress — create a compounding effect that wildlife managers cannot afford to ignore.
Weather: The Hidden Driver
Ask any wildlife biologist what controls EHD outbreak severity, and the first answer you'll get is weather. Buckley said weather strongly influences outbreaks. This year's outbreak started in July and continued as South Dakota experienced an unusually warm, dry September with some heavy rain. That combination — prolonged heat, drought stress, and episodic rainfall — is essentially a perfect incubator for the biting midges that transmit the virus.
Retired Game, Fish and Parks lead biologist George Vandel said those conditions — drier dry periods and wetter wet periods — can create the environment where midges thrive best: muddy areas that are sometimes covered by water and sometimes exposed to the air. That description captures the wet-dry cycle that defines floodplain habitat along the Missouri: exposed mudflats baking in October sun, punctuated by shallow pools and creek margins where midges lay their eggs. The river corridor, in other words, is ground zero for exactly the habitat that makes this disease dangerous.
Warm conditions can extend the period when the insects are active, while a hard freeze generally kills them off, bringing a seasonal outbreak to an end. EHD is a viral disease spread by insect bites, and warm weather of late is extending the infection period. The first hard freeze of the season normally kills the bugs — but that hasn't happened yet. South Dakota hunters are, in a very real sense, waiting on a killing frost the same way they'd wait on a cold front to push birds south. The freeze that ends the outbreak can't come soon enough.
How the State Is Responding: License Refunds and Regulation Overhaul
South Dakota's Game, Fish and Parks Department has not sat on its hands. Beginning well before the October spike in reports, officials laid groundwork for a management response that spans the entire season — and now that the disease has accelerated, they are moving further, faster.
Full Refunds in 16 Counties
Officials are offering full license refunds to hunters in 16 counties along the Missouri River corridor. The refunds are intended to provide relief to hunters whose seasons have been affected by the outbreak and related hunting changes. This is not a trivial financial gesture — South Dakota deer tags represent a significant investment for many hunters, particularly those who drew hard-to-get firearm permits in heavily pressured units after years of accumulated preference points.
Wildlife Division Director Tom Kirschenmann said the department may add counties as more October reports arrive. The door, in other words, is still open. The situation is fluid enough that what applies to 16 counties today might apply to 20 counties by the time the firearms season gets underway. "We're trying to be somewhat strategic about it, but we're also trying to be proactive about where we offer this up," Kirschenmann said. That statement, delivered to the commission in Pierre, telegraphs a department that knows it's managing a moving target — and isn't afraid to say so publicly.
Removed Licenses and Archery Restrictions
The refund program represents the reactive piece of GFP's response. But the proactive measures — changes made before the season even opened — are equally consequential for hunters who planned their fall around South Dakota deer. In response, the state has reduced hunting opportunities in several affected areas, including removing some youth and mentored deer licenses and modifying statewide archery regulations.
The department removed mentored and youth deer licenses in nine southeastern South Dakota counties where outbreaks have affected deer in the past two years. It also removed 62 unsold licenses, two in McPherson County and 60 in Dewey County. The state changed statewide archery license rules, which previously allowed hunters to take any deer, to buck-only licenses.
That last change — converting every archery tag in the state to buck-only — is the one that likely hit the most hunters in the wallet and in the freezer. That means taking a doe with a bow or muzzleloader is completely off the table this season. State wildlife biologists made this change to protect the area's antlerless population following recent severe winter weather, drought conditions, and epizootic hemorrhagic disease outbreaks that took a hit on local herds. For hunters who count on filling the freezer early with an archery doe — a strategy that frees up firearm tags for a mature buck later — this is a genuine disruption to a carefully planned season.
East River and West River Tag Cuts
Before the archery season even opened, the Commission approved tag reductions across multiple firearm units, with East River deer cut by 700 licenses across 12 hunting units, and West River deer cut by 700 licenses across three hunting units. GFP reduced East River deer licenses by 700 tags across 12 hunting units, with cuts ranging from 20 to 50 percent per unit. The reductions are not spread evenly — some units absorbed heavier cuts than others based on local herd data.
The youth and mentored season suspensions in the southeast are perhaps the most striking policy move GFP has made. In nine Southeast River counties — Yankton, Davison, Bon Homme, Clay, Hanson, Hutchinson, Lincoln, Turner, and Union — GFP suspended youth, mentored, and apprentice deer seasons entirely for 2026. This is a full suspension of those season types in those counties, not a reduced-quota situation. In 2025, those seasons produced 255 deer harvested across the nine counties. GFP is withholding that harvest pressure while the herd recovers in the most EHD-impacted zone in the state. Pulling 255 deer of harvest pressure sounds modest in isolation, but in units where the breeding population is already stressed, every doe counts.
Asking the Public to Help Track the Disease
GFP has also leaned on a time-tested tool in wildlife disease management: the eyes and ears of people who spend the most time outdoors. South Dakota wildlife officials are asking hunters, landowners and others who see deer often to report sick or dead deer as hemorrhagic disease continues to spread across the state.
The department asks people to report sick or dead deer via methods listed at gfp.sd.gov/contactus. Buckley said officials enter reports into a system that updates the department's public online map. That map — with red dots for confirmed EHD cases and black dots for suspected ones — is updated in near-real-time and provides a geographic picture of where the outbreak is most severe. It also helps officials determine which counties warrant refund eligibility as the season progresses.
Anyone who finds a dead or visibly sick deer should avoid handling the animal and report the sighting to South Dakota Game, Fish and Parks. And there's an important food-safety note for hunters who harvest a deer in an affected area: wildlife and health agencies do not recommend eating meat from a deer that was visibly sick. A deer that was harvested legally and showed no obvious signs of illness is generally considered safe, but hunters should use judgment and consult GFP guidance when in doubt.
The Bigger Picture: EHD in the Context of a Multi-Year Herd Struggle
The 2026 outbreak doesn't exist in a vacuum. It's arriving on the heels of what has been, by any measure, a rough stretch for South Dakota's deer herd. South Dakota GFP cited a convergence of factors driving the 2026 restrictions: a severe 2025–26 winter, spring flooding, drought stress on habitat, and multiple years of epizootic hemorrhagic disease outbreaks concentrated in the Southeast River region. Poor fawn recruitment in recent survey years compounded the pressure.
That cascade of stressors matters for hunters trying to understand why GFP is moving this aggressively. When a herd is hit by one major event, it typically rebounds within a few years. When consecutive winters, a drought, a flood, and a disease outbreak pile on in rapid succession, the math changes. Does that would have carried the next generation of fawns were killed by EHD in 2024 and 2025. Fawns that survived those previous winters then faced a brutal 2025-26 freeze. The herd heading into the 2026 season was already operating at a deficit before the midges emerged in July.
Although EHD can cause significant local deer mortality, the severity of an outbreak can vary by location and year. That variability is both reassuring and frustrating. It means a county that was devastated in 2024 might dodge the worst in 2026 — but it also means even experienced biologists can't predict with precision where the outbreak will spike next. The pattern of spread follows the midges, which follow the weather, which no one can control.
Historical Parallels
South Dakota is not alone in its EHD struggles, and the disease's history across the Great Plains and Midwest provides useful context. The 2012 drought year triggered one of the worst EHD outbreaks in recorded history across the Upper Midwest and Great Plains, killing tens of thousands of deer across multiple states. States like Michigan, Indiana, and Nebraska all recorded significant mortality events tied to that summer's historic heat and dry conditions. The pattern is consistent: drought creates the mudflat habitat midges need, warm temperatures extend their season, and the deer pay the price.
What makes South Dakota's response in 2026 notable is the speed and scope of the management reaction. In previous outbreak years, many states waited until post-season harvest data confirmed population impacts before adjusting the following year's quotas. South Dakota is making real-time in-season adjustments — removing licenses, converting tag types, suspending youth seasons, and issuing refunds — while the outbreak is still actively developing. It's proactive wildlife management at a scale rarely seen in a single deer season, and it reflects hard lessons learned from previous outbreak years when delayed action meant it took three to four seasons to restore herd levels.
What Hunters Should Do Right Now
For any South Dakota deer hunter holding a tag or planning a trip to the state this fall, the situation demands active engagement with GFP's updates rather than passive waiting. The list of refund-eligible counties may grow. Hunters should check the South Dakota Game, Fish and Parks Department's official updates for the list of affected counties, current restrictions and instructions on how to request a refund.
Hunters who are on the fence about hunting their unit should also be thinking about the practical realities on the ground. Seeing dead or sick deer in the field doesn't mean the entire population has collapsed, but it does mean hunting pressure at the normal rate could set a weakened herd back further. The buck-only archery rule is one tool to reduce that pressure — but hunters can also contribute voluntarily by passing on does and focusing on mature bucks in hard-hit units, regardless of what their tag allows.
For anyone hunting along the Missouri River corridor or in the southeast counties, the terrain itself warrants extra attention this fall. Areas near mudflats, shallow creek mouths, stock ponds, and river edges — exactly the spots that hold deer — are also exactly where EHD-infected animals seek water in their final hours. Finding a dead deer in those spots is more likely than in a normal year, and knowing what to do (don't handle the carcass, report it to GFP) matters.
Looking Ahead: When Will It End?
The cold truth — no pun intended — is that the only thing that will end this outbreak is sustained cold. The disease is most common during warm weather and is expected to continue until colder temperatures and a hard frost kill the insects that spread it. With South Dakota's October running warmer than average through mid-month, that freeze is still pending as of this writing.
When it does arrive, the outbreak will stop spreading almost immediately. EHD does not survive in deer long enough to continue killing animals once the vector is gone. Unlike chronic wasting disease, which persists in the environment for years and continues spreading through direct deer-to-deer contact, EHD burns out with the bugs. A killing frost in late October means that by November, when most firearm hunters hit the field, the active transmission phase will likely be over.
But the mortality already on the books won't reverse itself. The deer that died between July and mid-October are gone, and their absence will shape population dynamics in affected units for at least two to three seasons. GFP's management response — aggressive, real-time, and biologically sound — is aimed at minimizing how deep that hole gets. Whether it's enough to protect the herd while giving hunters a meaningful season will be the question that plays out across the cottonwood bottoms and prairie draws of South Dakota all the way through January.
For the men who plan their fall around the deer seasons of the Northern Plains — who save preference points for years, book travel logistics months in advance, and put real money and time into these hunts — the 2026 season is a test of patience and adaptability. The state is doing its part. Now it's on hunters to do theirs: stay informed, stay flexible, and let the herd come first.
