A collared pronghorn took her last breath on Feb. 16. The adult doe’s remains were found on the south end of the Pinedale Mesa. 

Another marked-and-tracked doe died a couple days later, just 500 yards away. A week later the third adult female went, her final resting place a mile or so north of her migratory compatriots. 

With that, every collared animal that traveled the celebrated Path of the Pronghorn in 2022 was dead. 

It was a grim sign for a migratory pronghorn population that has thrived in recent years. Now, following the deadliest winter on record in which a disease outbreak compounded fatalities, the fate of the long-distance travelers that winter in the Green River basin but sojourn for the summer in Grand Teton National Park, the National Elk Refuge and along the Gros Ventre River is unclear. Wildlife scientists aren’t sure how many remain.

“Anything’s possible, right?” Brandon Scurlock, a regional wildlife coordinator for the Wyoming Game and Fish Department, said. “But I would have to think that some of those animals made it and will make that migration.” 

But the outlook is grim, with the large majority of animals from the larger Sublette Herd likely dead, according to Scurlock. Pronghorn in the herd were being closely studied as the state considers whether to recognize and protect a route that remains undesignated due to political pressure from industry groups. The monitoring effort tracked 83 does throughout the herd as recently as December. By Tuesday, when Scurlock spoke to WyoFile, just 21 of them were still alive — including zero of the Jackson Hole migrants.

“We lost 75% of our collared animals,” he said. “It’s erroneous to [extrapolate] that 75% to the entire herd, but that’s our best indication of survival. If we did have 400 or 500 [Jackson Hole migrants], our best guess is that 75% of those might be gone.” 

A young pronghorn buck’s final resting place in 2023 was a hilltop over Highway 189 along the east slope of the Wyoming Range. (Mike Koshmrl/WyoFile)

In Jackson Hole pronghorns’ favor is that the migratory population has thrived of late. Counts in 2020 and 2021 were the highest on record

If the so-called Path of the Pronghorn does live on, it’s all but assured that drastically fewer animals will make the journey, which cuts through gas fields, skirts coming-soon subdivisions and treads over a mountain pass

Lost before 

An archaeological site along the migration route at Trappers Point holds evidence that humans have hunted pronghorn along the path as long as 6,000 years ago.  

But even within that long history, the Path of the Pronghorn has faded before. 

Joel Berger, a Wildlife Conservation Society researcher and former Jackson Hole resident, was part of the multi-agency research team around the turn of the century that first mapped the route. The science led to the Bridger-Teton National Forest amending its management plan, in essence creating the first federally designated migration corridor in the United States. The southern reaches remain undesignated — to the chagrin of some wildlife advocates

“Early reports were a couple of thousand around the turn of the century, then they went extinct locally in Jackson,” Berger said. 

The migration route was lost, he estimated, between about 1910 and the 1950s. 

“The pronghorn were just all shot out,” Berger said, “because we didn’t have good conservation in those days.” 

Green River basin pronghorn evidently learned the ancient route into modern day Teton County again some four decades later. Berger likened them finding their way back to a pinball player’s inevitable outcome. 

“What happens? Ultimately, the ball ends up in the hole, right?” Berger said. “From our GPS data we know they were bouncing all over, but the only access into Jackson was the single route.” 

The famous Path of the Pronghorn migration, pictured, is typically completed by early June. It’s unclear how many animals survived the winter of 2022-’23 to make the journey. (U.S. Geological Survey)

Fast forward to the present, and management of the pronghorn herd is much more deliberate and science-based. 

Game and Fish and the National Park Service not only survey the Jackson segment annually, the state agency keeps close tabs on numbers within the entire herd, which spans western Wyoming from Green River to northern Grand Teton National Park. The population breached 60,000 in the early 2000s but was last estimated at 43,000, Scurlock said. 

In past bad winters over the last couple decades the herd has fared OK.

“We know we did lose some pronghorn in ‘16-’17, but this winter was unprecedented in terms of the number of days below zero and the depth of the snow on the winter range. ” Scurlock said. “We just didn’t see these large foci of carcasses [in ‘16-’17].” 

Wildlife managers like Wyoming Game and Fish Department biologist Gary Fralick, in the background, say there will be years of recovery before western Wyoming ungulate herds fully recover from the deadliest winter on record. (Mike Koshmrl/WyoFile)

In the wake of winter 2022-’23, there are conspicuous concentrations of death scattered throughout the region. Motorists can see them without leaving their vehicle in places like the East Fork hill, located on the east side of Highway 191 between Farson and Boulder. 

“We’re seeing these clusters of animals on the landscape that are now dead,” Scurlock said. “Rock Springs to Boulder, over to Big Piney, down by Kemmerer.” 

Outbreaks of mycoplasma bovis, a new affliction in the Green River basin that causes a deadly respiratory disease, have been observed in the hardest-hit areas, he said. The carcass of the first Jackson Hole migrant that died this winter was shipped to a Laramie laboratory and tested positive for the disease. 

The verdict

There are a few bright spots better for survival along the southern fringes of the Sublette Herd’s high desert home, Scurlock said. Those areas, he said, include the Red Desert between the Killpecker Sand Dunes and the town of Superior and the bluffy country overlooking Interstate 80 near James Town.

Although it’s an open question what remains of the Jackson Hole segment, answers should come through in the next couple weeks. 

GPS collar data suggests that up to 75% of the Sublette Pronghorn Herd perished during the long, cold winter of 2022-’23. This small group made it through the winter alive. (Mark Gocke/Wyoming Game and Fish Department)

“In a nutshell, we won’t know until they show up in June,” Game and Fish wildlife biologist Aly Courtemanch said. 

State and federal agencies will partner to do a more-thorough census of what’s left later in the summer. Game and Fish has drastically reduced hunting opportunities to give the herd its best shot at recovery. Doe and fawn hunting — which has the most impact on populations — has been eliminated in all hunt areas roamed by the herd, Scurlock said. 

“They are fairly fecund, and they can bounce back pretty quick just because they have twins as the norm,” he said. “Our plan is to give the herd the maximum opportunity to bounce back by eliminating that reproductive harvest.” 

Still, the population’s starting point will likely be significantly lower than wildlife managers have seen in their lifetimes. They’re beginning to see what that looks like. 

Game and Fish biologist Gary Fralick’s territory doesn’t cover the Sublette Pronghorn Herd, but he drove through a swath of its habitat on Monday on his way to take a look at what’s left of the Wyoming Range Mule Deer Herd

“Since I’ve been around, in that country it’s always the pronghorn leading the deer. And they’re not there.”

Gary Fralick

Typically there’d be “several hundred” pronghorn foraging this time of year on pastureland and in the sagebrush from the Hoback Rim down to Daniel Junction, he said. 

Fralick, a 30-year veteran at his biologist post, saw only 11 animals. Their absence, he said, isn’t because of a delayed migration. It’s because they’re dead. 

“Since I’ve been around, in that country it’s always the pronghorn leading the deer,” Fralick said. “And they’re not there.”

Dead pronghorn litter the roads that bisect the La Barge gas field in western Sublette County in 2023. (Mark Gocke/Wyoming Game and Fish Department)

Mike Koshmrl reports on Wyoming's wildlife and natural resources. Prior to joining WyoFile, he spent nearly a decade covering the Greater Yellowstone Ecosystem’s wild places and creatures for the Jackson...

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  1. I just drove Rt 28 between Farson and the Sweetwater River. Quite a few pronghorn are hugging the fence line south of Rt 28. I estimate at least a hundred along the whole stretch of about 40 miles. They’re probably trying to migrate north.

    Maybe some kind of fence opening (intermittent / scheduled / coordinated with traffic) would help? Pending building several of those million dollar wildlife crossings.

  2. Why not mention wildlife unfriendly fences? Obviously, the pictured herd was stopped by one.

  3. So antelope season will continue no matter what? Never mind that there are no antelope!!
    Our Game and Fish Department will survive selling licenses.????

  4. Why is it that Oregon, Idaho and Utah feed during harsh winter’s but the Wyoming Game and fish would rather just watch our game herds starve? The deer herds were already down 50 percent according to a biologists I talked to a few years ago, now we’ve lost all the fawns from last year and many of the pregnant does that would have given birt this year. These other states have special pellets that the game can digest but Wyoming always refuses to feed. Governor Gordon should fire the head of the Wyoming game department for dereliction of duty. Of course the only thing they care about is revenue. I’m really surprised they didn’t open the season for nine additional doe fawn tags like they did in 97. The Wyoming Game and fish department are basically useless when it comes to managing big game.

  5. They mostly froze and or starved to death due to the very very tough winter in southern Wyoming. I believe hunting is regulated by professional G/F people experienced in the number of animals that can be supported on the available food supply. Hunters had absolutely nothing to do with it, except I suppose you can say they harvested and thus prevented even more animals from dying and rotting.

  6. “ A HUGE point of clarification that the Wyoming Game & Fish Dept. through the Wyoming Game & Fish Commission did not eliminate the taking of a Doe or Fawn Antelope for the 2023 hunting season. What they did was eliminate all additional Doe/Fawn licenses. What people are missing is that the licenses that will be issued are known as an “ANY ANTELOPE” license meaning just that, any antelope of either sex or age can be taken.

    *** copied from an earlier post by Mike Shmid.

    ***Lets be honest about the Fish and Game. Where do the majority of the funds that support Fish&Game source from. Hunting? Ranching? Anglers? Commercial Fishing?

    Most members of the public are unaware that a public agency protecting a public resource is not funded by public dollars.

    We need states to take ownership and be accountable for vulnerable wildlife and their habitats by investing more dollars in agencies responsible for protecting them, to actually protect them.

  7. So, cattle, bison now pronghorn so its possible to also spread to deer & elk? My guess would be yes. Probably too late for Wyomings pronghorn.

  8. Just a point of clarification that the Wyoming Game & Fish Dept. through the Wyoming Game & Fish Commission did not eliminate the taking of a Doe or Fawn Antelope for the 2023 hunting season. What they did was eliminate all additional Doe/Fawn licenses. What people are missing is that the licenses that will be issued are known as an “any antelope” license meaning just that, any antelope of either sex or age can be taken.
    I wrote to the G&F Commission before the season setting meeting last month. My ask was to change the “any antelope” tags to “buck only” tags. Many others wrote in and testified at the meeting asking for the same. The Commission had a good discussion on this idea, but ultimately chose not to change the “any antelope” designation.
    My fear is that the male population of any big game species naturally is much less than the female segment. With the devastating losses this past winter many of the bucks perished because they go into the winter with less body fat as a result of the fall rut/mating season when they spend more time chasing and breeding rather than eating which burns up their fat reserves. Because of this fall activity many of the bucks perished. So with fewer bucks on the landscape, coupled with the difficulty in drawing an Antelope tag, I fear that many hunters will not find a buck and will fill their tag with a Doe or Fawn. Huge mistake by the Wyoming Game & Fish Dept. for not recommending it to the Commission and an even bigger mistake by the Wyoming Game & Fish Commission for not changing it especially since they have the authority to do so.

  9. I am wondering if the political aspect figures into this. Since the govt wants the land could they have been made sick? I mean they did it to people so why not animals?

    1. What are you talking about? “the govt wants the land”

      Nearly all of this occurred on public lands, which are owned by all of the American People.

      They most likely got the disease from domestic cattle.

  10. Wyoming, smallest population in the country with all that open space. And the wildlife takes no precedence over the cattle on our public lands. How awful to watch the horrible management of our wild horses as they zero out herds.
    Now our amazing pronghorn may be lost too, the elk and mule deer devastated too.
    Why can’t there be sane scientific management of the most beautiful part of OUR Wyoming!
    Our state is being destroyed by radical politics and lack of science. The BLM or Game and Fish, knew these herds were suffering and did zero!
    Thanks to the others who posted here that know facts. Devastating article.

  11. Perhaps you should look to the sky and watch all the aircraft spraying chemicals and metals, and possibly biological death over this country.

  12. Stop giving permits to kill them for a few years until you figure out what is killing them and and make a plan to get them back to a sustainable herd before it’s to late its Rediculas when think about it about let’s let another filthy rich cattle rancher feed his cattle full of a bunch of crap on state or federally owned property for free ?

    1. A “filthy rich cattle rancher”. What an ignorant, stupid, I’ll informed, liberal parrot remark to make. Cattle ranchers aren’t “filthy rich”, most of them and farmers by the way, barely get by. Bet you love to eat 3 squares a day, and have a nice juicy steak or hamburger. Quess what, without “filthy rich cattle ranchers” and farmers you’ll get pretty hungry, and guess what you’ll be paying for the imported trash that’ll be left on store shelves. Please think for yourself before you make ignorant, liberal parrot remarks.

      1. Welfare ranchers in wyoming could all stop tomorrow and the cattle market would barely notice.

        If a rancher can’t survive without government handouts, they need to find a new career.

  13. This state has just suffered its first really bad winter of this century. Livestock losses were heavy, and all species of wildlife were hard hit, not just the antelope. Migration corridors or not, during such an event, losses are heavy. In our area, animals migrate, mostly onto our deeded lands where we irrigate and produce forage for wintering livestock, and generally they winter well there on that enhanced habitat. This winter they died right alongside our livestock. It was not disease, it was several feet of snow, record cold temperatures, and double-digit sustained winds, over the course of several months. There was no place they could or would have gone where conditions were any better. “Mother Nature “ can be harsh, as it was before any development was here. To blame this on industry is a tactic to promote an agenda that good people that don’t understand buy into, and pretty soon there is a consensus to hurt people on the land who are actually the last best protection for open spaces.

    1. Predictable deflection defending welfare ranching and the mismanagement of the public land they lease.

    2. Thank you, well said. Do these people never make a connection between farming/ranching and their food on the table?

  14. I viewed these wonderful animals while traveling to and from the Grand Teton mountain range. I felt privileged to encounter these creatures. I thank God for them and also good scientific management. I pray the herds bounce back and we have the wisdom to help. Thank you for this informative article!

  15. Hi, I live in Boulder, Wy(4th generation)
    As unprecedented the snow, and cold (acute) were this year, the last 2-3 years were in contrast historically mild.
    The antelope got comfortable on Paradise Road and never made their annual trek down to flaming Gorge. That never happened in 60’s- 80’s as herds grew. I sat through 2 hours of comments March 30 in Pinedale from the Governor and Wyo G&F. Not one word about climate change ( four letter word here, I understand) but the antelope and mulley’s don’t. This novel
    Pneumonia (first discovered 2019 eastern part of state), will only get worse most likely. So, climate has to be part of the conversation if you want a game plan going forward on how to help these iconic animals!

  16. I’m sure that Teton County will want to show complete solidarity to the Jackson Hole “segment” and turn off its nat. gas pipeline for a couple, three years. And then there is that airport in critical grouse habitat in a Nat. Park. The Game and Fish will deal with this better than the media and litigators. It was a long winter.

  17. My question is what is the probable source or reservoir of Mycoplasma bovis? Since cattle are omnipresent in the area, is that the source? The “bovis” in the name would imply that.

    1. Yes, it comes from domestic cattle. Im sure there will be many wild theories, but like the old saying goes “When you hear hooves, think horses not zebras”

  18. A few years ago we had a bad winter in Fremont County, I had close to 240 antelope coming right into my cattle and feeding on hay with them.
    Bill Crump of the Game and fish came out and saw what was happening, he wondered why? Game and fish donated some hay to me to recompense for the hay the antelope ate.
    But now they still say antelope cannot eat alfalfa! ??
    It is my firm belief that G&F could have started out with some Grass hay and only fed a little for a while, then slowly got them used to regular grass – hay mix.

  19. Devastating article – From my Scarlet macaw and Great Green macaw conservation experience in Costa Rica, we’ve learned that protecting and conserving the geographical corridors for land animals has tremendous impact for all species all the way up to the sky.

    With regard to habitat intrusion on the part of ‘renewable’ power sources: I am particularly concerned about wind farms decimating bird populations. Perhaps individual conservation groups can work together to make this happen for the pronghorns which will benefit all (animals and humans).

    Keep up the great reporting.

  20. Could You bothering them with injections, collars and your contact cause transfer of any virus to them. With human error? Seems solar, windmill destroying more than helping , with destruction of birds, sea mammals on east coast unbelievable amount dead, bees, yeah teach is really helping, get ready to eat your crickets.

    1. The virus nearly certainly comes from domestic cattle. And there is almost no solar or wind development in this area, only hundreds of thousands of acres of natural gas pads in the middle of the corridor.

  21. Mycoplasma bovis is 1 of several bacterial pathogens associated with pneumonia in cattle.

    In my opinion one of the big problems here in wyoming is that cattle and sheep herds take priority Over the public trust and our wildlife. When cattle and sheep overgraze our public lands and destroy riparian habitat all wildlife and the public suffer. Remember its your land ie blm state and federal land. Its not the ranchers. Its not the 1860s anymore folks. I want the public lands to be off limits to domestic animals.

    1. As it should be… everything has a cost, everything… nothing is free of consequence, so why should ranchers make every one else bear the cost? I understand that it will make meat more expensive, but it should be, life is valuable!

  22. It all comes down to habitat. Tough winters, disease and other factors come and go. But if Pronghorn have quality habitat they will thrive. If they don’t, then population peaks and valleys will be lower with each passing decade.

    When I was young the numbers of Sage Grouse were impressive, probably 20 times what I see today, and we looked forward to the August opener every year. Now days, I don’t even bother to hunt. Are we going to let the same thing happen with Pronghorn?

    People blame oil and gas for the habitat destruction. True enough. But wind and solar field development is as bad or probably worse. There is nothing “green” about habitat destruction, regardless of carbon footprint. If we protect the habitat we’ll have wildlife. If we don’t, then articles like this are just the start.

    1. I agree totally domestic animals should be very limited to public grazing areas and leave for wild life. If hunting them need to stop so be it I am a hunter but the survival of wild life comes first.

    2. It was global warming hysteria that kills animals!
      Imagine the $ spent by Biden going to conservation. I live in rain drenched – no drought Calif, smarten up people!!

  23. Science–NOT Politics–should be the deciding factor in managing Wyoming’s wildlife. Let’s get this migration corridor (and others) designated to protect Wyoming’s wild future.

  24. Lets see if for once Wyo G&F actually does the correct thing and shuts down hunting in these areas for a year or two so the herds can recover, or if as usual, making money is the priority, and they just focus on that, sacrificing the correct wildlife management process, business as usual for them-

  25. This is so sad to read about the suffering of these beautiful animals. In the article it mentioned the birth of twins and eliminating them. I take it you’re going to kill them? Why would you do that? Have you given thought to providing food on their Journey that could have antibiotics in it to help clear up the condition?

    1. Katherine, you misunderstood the statement regarding the twins. They are eliminating the hunting of fawns and female deer to give them a better chance of getting their numbers back up.

    2. Katherine Napolitano- “eliminating that reproductive harvest.” Meaning they won’t allow hunting or will limit the number of tags. They are not eliminating the animals.

    3. You misunderstand the sentence– will “eliminate” the harvest, aka, cut back on the hunting season– I believe. It is an awkward sentence, so easily misunderstood.

    4. That might take to much money out of there pockets…. They couldn’t upgrade their toys and buy more. They forgot what they are there for they haven’t done anything for the wildlife in so long. They don’t want people who care about wildlife they want yes men people that will go out and shot a hundred head of elk with no questions asked…….

  26. Industry, big money really, has trashed out public lands and the wonderful animals that used to live wild and free. The BLM deliberately trashes our wildhorses and burros making sure to carry out the will of those who pay lobbyists in DC. Sickening

    1. “Wild horses and burros” have the capacity to double their populations every four years! Before the 1600’s, pronghorn didn’t compete with “wild horses and burros” (or any other domestic livestock) for forage.

      1. How about we start with fences? Surely if you cared you would advocate for tearing all those down? I wonder why you started at Horses and burros?

        1. I agree-fences are a huge impact to wildlife. The term “wildlife friendly fencing” is a huge misnomer. We need to look at areas that dont need to be segmented between every cow.

    2. The wild horse’s are a big problem. They are non-native to Wyoming and should be eliminated . They make mud holes out of the natural springs that the native wildlife need. They also eat much of the food that the big game needs to survive. It cost the tax payers hundreds of millions to keep these things corralled and fed. They could be sold to France for food.

  27. Please save these beautiful animals in ur state. Too many of God’s animals r dying & deserve better on this earth. Protect them as much as possible in the years to come from being hunted until the herds grow in size again. This photos r so sad it made me cry seeing all these animals dead all over the fields that they roamed to live their lives free.

  28. If you travel across the USA, other states don’t have great heards…they are only in Wyoming! Why can’t Wyoming government ” leadership”
    make it a priority to help…like having the University of Wyoming develop feed pellets for the antelope and commission some state dozens to clear areas for snow relief. I’m a Wyoming Conservative Member…I’d like to see results from my money!

  29. Just heartbreaking to read. The Northern Utah and NW Colorado deer herds got decimated too. Truly brings tears to my eyes, sadness and a sense of emptiness. I love those animals. I think the Game Departments have it right to drastically reduce the hunting numbers and have my total support. As much as I like to hunt I rather have them around then fill the freezer.

  30. This is a giant, blinking, neon sign, that migratory corridors need to be designated and protected.