Thunder Basin Grasslands Amendment License to Kill Prairie Dogs

Black-tailed praire dog. Photo by George Wuerthner

Years ago, I went out of my way to visit the Thunder Basin National Grassland. With a name like “Thunder Basin,” how could I resist.

The Thunder Basin National Grassland is located in northeastern Wyoming in the Powder River Basin between the Big Horn Mountains and the Black Hills. Short-grass plains dominate it.

The Medicine Bow National Forest released its Record of Decision for the 2020 Thunder Basin National Grassland Plan Amendment.

The purpose of the amendment is to make it easier to kill prairie dogs on the Thunder Basin National Grassland. Of course, the Forest Service (FS) does not explicitly say that, but that is the document’s result.

The black-tailed prairie dog is considered a “sensitive species” by the Forest Service. But they seemingly sacrifice the animals to protect livestock interests using our public lands.

Indeed, in making its decision to reduce the acreage of protected prairie dog towns on the Thunder Basin National Grasslands, the Forest Service specifically said one of its reasons for prairie dog control was to preserve the culture of local communities that have traditionally relied on livestock grazing.

It’s preferred alternative would reduce the area on the Thunder Basin National Grasslands where prairie dogs are protected from poisoning programs from 33,000 acres to 10,000 acres with the caveat that the occupied territory could be reduced to 7,500 acres during drought conditions before prohibitions against poisoning are enforced.

Baby prairie dog. Photo by George Wuerthner 

Besides, there will be ¼-mile boundary management zones around private and state land within which control of prairie dogs will be prioritized to reduce impacts to surrounding landowners. In specific circumstances, management zones may be expanded to ¾ mile. Priority for control will also be given within 1 mile of residences and where prairie dogs are causing damage to private or public facilities.

The FS explicitly says that the purpose of this amendment is to maintain “the history and culture of local communities that have traditionally relied on livestock grazing for economic vitality.” Of course, part of the local “custom and culture” is killing prairie dogs, so I guess the agency recognizes this and wants to accommodate parochial “traditions.”

The Forest Service relied on a local collaborative to come up with suggestions about prairie dog management. Like most collaboratives, the collaborative was dominated by local people like county commissioners, ranchers, and others who generally oppose prairie dog expansion, much less survival.

Not surprisingly, the amendment, the agency says: “is intended to help balance resource use when drought reduces forage available for livestock. They assert “that 7,500-acre drought objective will remove some competition for forage by prairie dogs during this time.”

In other words, there is going to be a lot of killing and not much habitat available to prairie dogs.

The amendment was prompted by the expansion of prairie dog colonies between 2015 and 2017.

The favorite means of “control” is Zinc phosphide. The chemical is mixed with a grain like oats and spread liberally across a prairie dog town. When consumed, zinc phosphide is converted to phosphine gas in the animal’s stomach. Vomiting, often hemorrhagic, is a common presenting sign in animals capable of vomiting. Tachypnea, ataxia, weakness, trembling, collapse, seizures, and death usually ensues, and any prairie dog unfortunate enough to consume the poison will die a horrific demise.

The management of prairie dogs on public lands is another example of how public agencies fail to protect the greater public interest and generally respond to local industry interests—in this case, the livestock industry.

The irony is several studies have demonstrated that livestock prefers to graze on prairie dog towns, as do bison.

Bison grazing on prairie dog town in North Dakota. Photo by George Wuerthner 

Their burrowing activities also increase soil nematodes and nitrogen on sites—all of which contribute to higher nutritional content, higher digestibility, and more live-plant to dead-plant rations.


There are five species of prairie dogs in North America–Utah (listed as endangered in 1973 and later downgraded to threatened species), Gunnison, white-tailed, Mexican (listed as an endangered species 1970), and the black-tailed.

Over the years, several individuals and groups, including myself, have petitioned to have black-tailed prairie dogs listed under the Endangered Species Act. They were considered “warranted” but precluded, but even this status was eliminated by the Fish and Wildlife Service in 2009.

Indeed, in 1997 I published a paper with the title: Black-tailed prairie dogs—heading to extinction? You can read it here.

Black-tailed Prairie dogs are residents of the West’s short grass plains and once were abundant from Texas (and northern Mexico) all the way into Alberta. Indeed, at one time, they were so plentiful that prairie dog towns stretched for miles across some regions. They have been eliminated over 95% of their range.

Given how numerous prairie dogs were, it is not surprising that they are considered a “keystone” species upon which many other species depend. Prairie dogs increase habitat heterogeneity and biodiversity at multiple scales across the landscape by creating burrows and areas of open grassland habitat that differ from the surrounding areas and serve as habitat for other species.

For instance, in Welfare Ranching: The Subsidized Destruction of the American West (2002), biologists Lauren McCain, Richard Reading, and Brian Miller write that over 200 species have been associated with prairie dog towns. The list of dependent species includes golden eagles, badgers, and long-tailed weasels.

Black-tailed prairie dog colony. Photo by George Wuerthner

Some like the black-footed ferrets rely almost exclusively upon prairie dogs for 90% of their diet. And the swift fox, a small native fox of the plains, also depends on prairie dogs and ground squirrels, and as recently as 1995 was also petitioned for listing.

Other species closely tied to prairie dog towns like the burrowing owl, ferruginous hawk, and mountain plover have all suffered severe declines.

At one time, there were an estimated 5 billion black-tailed prairie dogs in the West. Today the best estimates suggest there may as many as ten or 15 million. That sounds like a lot of animals, but keep in mind the passenger pigeon once numbered in the billions as well. Today all prairie dog species are severely reduced in numbers, fragmented, and periodically decimated by sylvatic plague, so entire towns are wiped out and abandoned.

In addition to plague, prairie dogs continue to lose habitat when grasslands are converted to row crops like wheat and corn, not to mention active poisoning programs by the federal and state governments. In some cases, “hunters” (I use the term loosely) get a big kick out of blasting prairie dogs to see the “red mist” of blood rising.

However, the biggest threat is the plague, which can annihilate prairie dog colonies. In 2017, a landscape-scale plague epizootic occurred in prairie dog colonies across the grassland, resulting in a decline to 1,100 acres of colonies by 2018.

This tendency for massive die-offs is why limiting prairie dog colonization and expansion is so dangerous. Prairie dog numbers can decline rapidly due to the plague and frequently result in local extirpation. Since prairie dogs only move 3 miles or less, once a town is lost, it may not be recolonized.


The federal government has spent years trying to restore and recover the black-footed ferret. The biggest obstacle is that few prairie dog colonies are large enough to sustain a viable ferret population. And natural events like drought can reduce colony size, coupled with poisoning programs and plague. Any one of these factors, or in combination, can quickly annihilate a local ferret population.

The 2013 Recovery Plan for Black-footed Ferret and 2018 Wyoming Black-footed Ferret Management Plan include objectives of maintaining a minimum of 341 breeding adults distributed among 5 or more populations in Wyoming; maintaining a minimum of 30 breeding adults in each population, with at least 2 populations containing a minimum of 100 breeding adults.

The Wyoming Ferret management plan admits that approximately 4,500 acres of black-tailed prairie dog colonies are necessary to support at least 30 breeding adult ferrets. More than 15,000 acres are needed to sustain at least 100 ferrets. Today there are only about 300 ferrets in the wild, and estimates suggest it will require 3000 to delist them.

Visitors viewing the largest intact prairie dog colony in North America which is in Janos, Mexico. Recent estimates put prairie dogs at 500,000 animals. The USFW recently reintroduced black-footed ferrets to this site. Photo by George Wuerthner 

Thus, the acreage objectives for prairie dog colonies in the Thunder Basin management amendment would not provide enough prairie dog numbers to support 100 breeding adult ferrets.


What all this suggests is that the federal government is not serious about protecting prairie dogs, nor their associated wildlife like ferrets, swift fox, and mountain plover if it conflicts with livestock operations on OUR public lands.

Many people enjoy viewing and watching prairie dogs. They are part of our wildlife heritage. Photo by George Wuerthner 

The management plan for Thunder Basin prairie dogs is a license to kill prairie dogs. It is another example of how federal agencies like the Forest Service put private businesses ‘ like welfare ranchers feeding at the public trough ahead of the public interest in protecting its wildlife and lands.

If we can’t have sufficient numbers of prairie dogs here on the Thunder Basin National Grassland, where can we?

The Forest Service did not attempt to answer this question in its amendment to the Thunder Basin Grazing National Grassland, but it is something that we need to ask repeatedly.







  1. Maggie Frazier Avatar
    Maggie Frazier

    “history & culture” has accounted for the deaths of large numbers of predator & prey species for hundreds of years. Whether its prairie dogs, sage grouse, wolves, coyotes, mountain lions wild horses buffalo & others. I think its time for history & culture to come into the 21st century – there have been thousands (at least) of species eradicated due to “history & culture”!
    Its past time for actual regulation of grazing allotments – and time to close them down. The taxpayers should be sick & tired of subsidizing livestock operations that only make up 3% of the beef produced here. Since people are eating less beef – that 3% really isnt needed.

  2. SANDY LEE Avatar

    Maggie Frazier agree with what you say but how do we fight what is a very bad situation in which everything is geared toward grazing and the native animals are just in the way? The normal American likes having these animals and it encourages visits to areas such as National Parks or areas where they can be found. The people make no difference it is all in grazing rights and the past.

    1. Maggie Frazier Avatar
      Maggie Frazier

      Honestly – until everyone is aware of the fact that we, the taxpayers, are paying for these livestock operators – corporations in many cases to destroy our public lands? Not to mention what has been and is being done to wild animals – driving them to extinction, frankly. I dont know. I’ve been writing & commenting to my “representatives” & elsewhere for years as have many others. A very large epiphany is needed!

  3. Gail Avatar

    Thank you, George. Sharing. I’m taking a guess that comparatively few of us understands the intricate politics of the livestock industry – the squatters and usurpers of our public lands. If only they’d be compelled to pay fair, significant grazing fees, maybe they’d just fade away.

  4. Beeline Avatar

    Get behind the third party movement. The Peoples Party.
    Keep insisting that you as a tax payer do not want to subsidize the ecosystem damage on public lands.

    America has not healed from what was done in the past. It has only gotten used to ecological damage. Remember that it was founded on the graves of Indians, the bones of buffalo, the pelts of millions of animals, the plumes of countless birds, the cutting of forests, the backs of slaves and entire species such as the passenger pigeon. Ecological crimes that we are still paying for today.

    1. Ida Lupine Avatar
      Ida Lupine


  5. Oakley Taylor Avatar
    Oakley Taylor

    It is inconceivable to me that people think the welfare of wildlife should be compromised to accomodate ranchers with their cattle on public lands. This is ridiculous! Why do we, as a nation, allow this to happen? Public lands belong to all of us; how much are ranchers paying to allow their profit incurring cattle to graze? Leave the wildlife alone and let them live their lives unhampered and free.

    1. Maggie Frazier Avatar
      Maggie Frazier

      The “going” rate for public land allotments is $1.35/month for each cow/calf pair! On private land its $20.00 or more! At one point in the last few years the rate was raised to $1.43 but apparently that was too much, so its back down.
      When you consider that the BLM treats one wild horse (about 500-750 lbs) as equal to a cow and a calf (1500 lbs+) – things are a bit out of wack.

  6. Ida Lupine Avatar
    Ida Lupine

    I know a lot of the public supports wildlife in theory, but I think there’s a disconnect there with eating meat.

    1. Maggie Frazier Avatar
      Maggie Frazier

      I agree, Ida – I think there are far fewer people still eating much or any beef. I havent bought any for years, and I’m not a vegetarian by any means. Look at all the “fake” meat now being produced – healthier too.

  7. GERALD JECH Avatar

    I have a theory, untested, that the reduction in prairie dog populations (and similar burrowing critters) has reduced the habitat (burrows) required by several (many) species of amphibians and reptiles. The near extinction of Wyoming toads in SE Wyoming, may be the result of the loss of critical habitat (burrows) related to reduced populations of prairie dogs, etc.

  8. Lyn McCormick Avatar
    Lyn McCormick

    Any chance the candidates for DOI Secretary under the Biden admin are negotiable for Science / Conservation-minded mgmnt of PL’s ? And, what is the latest data on the % of LS produced on PL vs private land East of the Mississippi ? It seems like a new strategy is in order; one that gives Stakeholders, particularly independent family ranching operations a financial incentive to participate in the Conservation efforts. The LWCF funding should be construed to conserve biodiversity rather than conserve private enterprise. The quickest way to reduce LS on public land is to provide Stakeholders with a financial incentive and meaningful employment to do so. If we continue with the same strategy of hoping another Corporate / industry friendly Admin will change things and / or wait for the trend of LS on PL’s to evolve away biodiversity will evolve away first. Just sayin . . .

  9. Craig Downer Avatar
    Craig Downer

    This is abominable! Not true multiple use, rather gross favoring of livestock interests and not justified in any balanced sense of ecological understanding. So wrong headed to further persecute and cruelly annihilate what remains of the ancient and ecologically important Prairie Dogs!

  10. N Mccormish Avatar
    N Mccormish

    This is worth noting, “that to maintain ‘the history and culture of local communities that have traditionally relied on livestock grazing for economic vitality.”’ when that tradition is only a few hundred years old, at most. Where is the concern for cultures (and yes, their economies) that thrived here for millennia sharing their lives with Prairie Dogs?

    Who decides where the cutoff is for a history worth “maintaining” and one worthy of utter destruction? Why do for-profit interests wag the tail of management on PUBLIC not PRIVATE lands?

    Why do we keep paying for this when it is so clearly in conflict with science, ecosystem health and the greater public good? Why do we endlessly repeat the same mistakes, generation after generation, learning nothing?

    1. Maggie Frazier Avatar
      Maggie Frazier

      Yes – WHY!


George Wuerthner is an ecologist and writer who has published 38 books on various topics related to environmental and natural history. He has visited over 400 designated wilderness areas and over 200 national park units.

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George Wuerthner