Wyoming's deer factory - the Black Hills - is emptier than ever

DEVILS TOWER-When the cyclic population of deer near Ogden Driskill's Crook County ranch peaks, sometimes he'll count as many as 800 whitetails grazing away in a single meadow.

That circle-shaped pasture draws in the deer because of its irrigated, nutritious grasses, and it doubles as a venue for nightly 6 p.m. hayrides targeted at tourists. The throngs visiting Northeast Wyoming pack onto a trailer towed by a tractor to enjoy views of the 5,112-foot-high spire that towers over Driskill's property. 

During the fall of 2021, staff at Driskill's Bear Lodge Cattle Company took on a new task: removing an eyesore that littered the meadow.

"We started dragging dead deer off and throwing them in the ditch," said Driskill, who's also president of the Wyoming Senate. 

The carcasses kept accumulating. What couldn't be seen still stank. 

"There were so many of them, we quit having the hayrides," Driskill recalled from his living room. "It smelled so bad along [the hayride route] with dead deer." 

The culprit explaining the deer deaths was a condition called epizootic hemorrhagic disease. EHD tends to be exacerbated by drought, which spreads near water where disease-carrying biting midges dwell. The more severe the drought, the fewer and smaller the watering holes, the more concentrated the midges and deer - and the worse the EHD outbreaks can be.

In the fall of 2021, the Wyoming Game and Fish Department documented one of the worst EHD epidemics on record. In places, it was every bit as deadly as the winter of 2022-'23, which killed upwards of 60% of collared adult deer and over 70% of adult collared pronghorn in some swaths of western Wyoming. 

"Our 2022-'23 winter [equivalent] was the summer of 2021 and 2022," said Joe Sandrini, a Wyoming Game and Fish Department biologist who's managed deer in the Black Hills region for over three decades. "There's ranches in that Hulett country that lost 80% to 90% of their deer." 

Driskill's ranch is square in one of the hardest-hit areas. So is Lee Jensen's property near Aladdin, on the banks of the Belle Fourche River. Going into the die-off event Jensen could easily tally 1,000 deer on his irrigated pastures, but by this fall the longtime cattle ranching family was hosting more like 100 to 150 animals. 

"It's just devoid," Jensen said. 

The lack of deer even influenced the day-to-day Jensen Ranch operations. In a normal year, Jensen has to drive slow and be careful when he's out irrigating at night on his four-wheeler. 

"You never know when you're gonna smoke a deer," he said. "This summer there was nothing moving. I had unfettered access to my roads."

Recovery after the rare back-to-back EHD outbreaks is going to take at least a couple more years, the rancher guessed. Wyoming Game and Fish's annual deer-counting "classifications" confirm the herds aren't recovering fast. 

Sandrini rendezvoused with WyoFile at an Interstate 90 rest stop while on a break from counting deer from a helicopter on the slopes of the Bear Lodge Mountains. Mule deer, too, aren't faring especially well right now in the Black Hills region - which is the story of the species in much of modern Wyoming. Both deer species are native to the state's northeast corner.

Bottom of a trough

Mule deer numbered an estimated 13,500 in the Black Hills Herd after the 2022 hunting season, down from a recent high of over 32,000 in 2017 and now fewer than half the herd's 30,000-animal objective. 

"Deer numbers up here cycle, and we're in the bottom of one of the lowest troughs that we've been in - for both species," Sandrini said. 

Whitetail have had it just as bad on the herd-wide scale. Although south of I-90 death rates weren't as bad, the EHD outbreaks in 2021 and 2022 were harsh enough to lop the Black Hills Whitetail Herd by a big margin. 

"We went from an estimated population of about 42,500 to 28,250," Sandrini said.

Go back a few more years to the most recent whitetail population peak in 2017, and numbers were at 62,500. That means the species has fallen off by more than half in what's normally a productive landscape that grows a lot of deer. 

Overall, Sandrini estimated there are fewer deer in the Black Hills and Bear Lodge Mountains than at any other point during his 32-year tenure in the region, which began in 1992 as a warden trainee. 

Ordinarily, this area is unquestionably the most deer-dense landscape in Wyoming.

"In the last 10 years we've averaged about 10% of the mule deer harvest and a third of the whitetail harvest statewide - and that's in just 3% of the landmass of the state," Sandrini said. 

Combined, he said, around 20% of all deer that hunters kill of both species in Wyoming are taken down in the six northeasternmost hunt areas where the Black Hills mule deer and whitetail herds dwell.

When populations run high, many Crook and Weston county residents believe there are far too many deer in the Black Hills herds. Driskill's Honda Pilot, which topped 337,000 miles in late November, is plenty familiar with whitetail deer. 

"This vehicle is on liability insurance, because it's hit two," Driskill said while out on a drive touring his hayfield. "Virtually everybody that lives here has hit a deer."

Driskill said he's OK with feeding 400 or 500 whitetails alongside his cattle at his hayfield. But he's less tolerant of the species when numbers climb up toward four digits. 

"The deer get in these pods on the alfalfa, and they love the alfalfa," Driskill said. "They'll literally destroy your hay. Everything's got to be game-fenced." 

Pendulum swings

Jensen saw things similarly: "From my standpoint as a landowner, there were too many deer," he said. "Now we've swung the pendulum 180 degrees." 

Game and Fish faces challenges if the goal is to hold the Black Hills herds steady in population. When whitetails are thriving, there is far more supply than demand for hunting licenses.

"We can't control [numbers] with hunting, we just can't," Sandrini said. "That's mostly because we don't have enough access for doe harvest on private land." 

Ratcheting up doe hunting on the Black Hills National Forest isn't a good solution, the biologist said, because it's not where damage is occurring and it's the most "heavily used public land in the state." Every other fawn born in the forest is a buck, he said, and Game and Fish "needs those" antlered animals to "give to hunters." 

Driskill's take is that the state agency could be doing a better job holding deer numbers steady, which he believes would help temper the depths of crashes. He's long been an advocate for statutorily separating whitetail and mule deer - an idea that the Wyoming Wildlife Taskforce (on which Driskill sat) also recommended.

But at least for the next few years, dealing with too many deer in the Black Hills and Bear Lodge Mountains is not something wildlife managers and landowners have to worry about.

"Financially, I wanted to see the numbers down, but I don't believe that anybody wants to see them this low," Jensen said. "We've seen population swings, but we've never seen this kind of swing." 

The majority of locals share the sentiment. Sandrini recently surveyed landowners within the Black Hills herd units and found that 68% deemed mule deer numbers too low and 53% believed there were too few whitetail deer. 

State biologists are seeing a mixed bag when it comes to recovery. Fawn numbers and survival rates in mule deer in 2023 were "pretty good," and high enough to "start digging us out of a hole."

"Whitetail, not so much," Sandrini said. Both fawn production and survival in the whitetail herd have been "pretty poor," he said, which has also been the case for nearby whitetail herds. 

But eventually, the herds are bound to come up. 

In recent history, the Black Hills have been one of the more productive places in Wyoming for growing mule deer. And it's prime habitat for whitetails, too. If there are two or three consecutive years of good fawn production and survival, the region will be "back in the deer business," Sandrini said. 

After that, the process might cycle all over once again.

"We just don't get enough harvest to control deer when they're doing well," Sandrini said. "And then we get a harsh winter or these disease outbreaks and we crash."

WyoFile is an independent nonprofit news organization focused on Wyoming people, places and policy.