Park officials in Colorado have no choice: they must close the Rocky Mountain Arsenal National Wildlife Refuge. Why? Because an age-old and fatal disease has started to rear its ugly head again. Yes, certain animals have become infected with the plague – a deadly disorder that ran rampant across Europe in the Middle Ages. But the creatures to blame may well surprise you.
Rather unsettlingly, this isn’t the first plague outbreak in modern times. Various costal cities in the U.S. have had to deal with infestations of the disease, in fact, with Los Angeles being the most recent victim – until now, that is. And so when Colorado officials realized what was happening in August 2019, they acted quickly in a bid to prevent history from repeating itself.
As strange as it sounds, though, the resurgence of the plague in Colorado may not be the craziest part of this tale. That’s because the animal to blame for spreading the deadly disease this time around isn’t what you might imagine. The 15,000-acre Rocky Mountain Arsenal National Wildlife Refuge contains a slew of noteworthy species, you see. And the creature responsible is arguably one of the least harmful-looking ones around. So, how did it become infected?
For someone to contract the bubonic plague – a disease that has persisted for thousands of years – a bacterium called Yersinia pestis must enter the skin. And so the most telling sign that a person is infected will be at these entry points. Sufferers, you see, will have enlarged, achy lymph nodes in the area – and sometimes, they’ll even burst open.
In most cases of the plague, the lymph nodes in the thighs, armpits, groin or neck tend to bulge out. And along with developing these lumps and bumps, some sufferers deal with gangrene in their extremities, including the nose, toes, lips and fingers. This side effect is a result of the underlying tissue dying, and the infection can lead to sepsis, too.
Shockingly, the bubonic plague passes through a tiny parasite: fleas typically carry it from host to host. These insects experience none of the effects of the the vicious disease that they transport. But when one bites another creature, the infection is spread to its lymphatic system. And this transfer typically occurs between fleas and rodents.
In most cases, black rats bring the plague close to human populations. They prefer to live close to people as opposed to in basements or drainage systems, you see. Once infected with the disease, the rats perish within two weeks, leaving the fleas that feed on them to seek out new hosts. And because the rodents prefer to find shelter near humans, the fleas move onto people after about three days without fresh food.
Before advances in modern medicine, the plague could wipe out massive portions of the population. An outbreak in the sixth century, for instance, caused between 25 and 50 million deaths. But the bubonic plague’s reappearance in the Late Middle Ages – between 1340 and 1400 – still stands as the deadliest breakout of disease ever recorded.
On this occasion, infected fleas and rodents made their way from Central Asia into Italy. Mongols attacked an Italian trading post in the Crimea, and the Europeans unknowingly fled with plague-carrying parasites on their ships. First, people living on the Black Sea started to suffer, before the disease spread outward as residents fled from city to city. And a shocking number of people eventually succumbed to the illness.
Yes, in the end, the Late Middle Ages’ bubonic plague outbreak became the deadliest of all time: it knocked out a whopping third of the entire human population of Europe. Historians surmise that the epidemic forever changed European society – and not just because more than 30 percent of them had perished.
You see, the plague seemed to show people the value of their lives – or the lack thereof. Certain historians suggest that mass mortality cheapened human existence and livelihoods. And as such, battles became more frequent. Crime, revolt and persecution increased, too, supposedly as people seemed to realize that their lives had less worth than they had once thought.
Three hundred years passed, and during this time Europe saw plenty of bubonic plague outbreaks. The last widespread occurrence in England would take place in the mid-1600s. And this time, London dealt with a horrendous pandemic that lasted 18-months, during which time roughly 100,000 of its residents died of the disease. Unfortunately, you see, multiple factors made the city a perfect breeding ground for the bubonic plague.
At the time of The Great Plague, London spanned just 448 acres, while today, it is far larger. And back then, the city was entirely enclosed by a large wall to protect it from raiders. What’s more, people in London’s poorer neighborhoods lived in squalor with piles of rubbish and fecal matter scattered in the streets.
Sanitation workers were given the unpleasant task of getting rid of the filth in which London’s poor lived. But this was achieved by simply dumping the worst of it outside of the city walls, where it would build up in mounds, decompose and cause a horrendous smell. There, shanty towns built to shelter the poor became infested with rats. And these rodents, of course, feed on garbage and animal excrement.
So, when The Great Plague reached London in the midst of the 17th century, it soon spread from the docks. And local government officials subsequently implored citizens to start cleaning up outside their homes to prevent further outbreaks – to no avail. As a precaution, then, most rich people left the city altogether as the disease swept through London, and businesses closed down indefinitely. But of course, in the meantime, thousands died.
Meanwhile, the plague has only made its way to the U.S. a handful of times; the most noteworthy outbreaks happened in the 19th and 20th centuries. In these cases, the source of the disease was probably China, which had had a major outbreak of its own in the mid-1700s. And, once again, American port cities saw the worst of the plague once it made landfall.
When the plague traveled from China to the U.S., the resulting outbreak became known as the modern pandemic. The deadly disease raged along shipping routes from the mid-1800s until the early 1900s. And locales such as San Francisco’s Chinatown, Oakland and the East Bay experienced the worst of it.
The last American outbreak of the plague occurred in Los Angeles in 1924. But wild rodents continue to carry the disease, which means that new cases do pop up from time to time. For instance, 16 people contracted the plague in 2015, two of whom caught it while visiting California’s Yosemite National Park.
Indeed, most cases of the plague in the U.S. are recorded in states that are known for their wildlife and outdoor pursuits. That’s why people are most likely to contract the infectious disease in southern Colorado, California, southern Oregon, northern Arizona, New Mexico and western Nevada. Overall, though, your chances of coming down with the plague are relatively slim: between 1900 and 2015, the country only experienced just over 1,000 reported cases.
Still, authorities take instances of the plague very seriously. And so in July 2019, when fleas infected with the terrifying disease began attaching to one of the species in the Rocky Mountain Arsenal Wildlife Refuge, officials took swift action. Specifically, the United States Fish and Wildlife Service shut down the area, which sits outside of Denver, Colorado.
The Rocky Mountain Arsenal Wildlife Refuge’s name is a legacy of the 15,000-acre area’s interesting history. In days gone by, the plains played host to large herds of bison. And Native Americans lived off of the land, too, following the large mammals as they migrated. But settlers who moved west went on to claim the land, using it to raise livestock and grow crops instead.
Then, on December 7, 1941, Japanese warplanes attacked the U.S. fleet at Pearl Harbor, sparking the country’s entry into World War II. In the wake of the assault, the U.S. Army took over this region of Colorado, transforming it into a hub for weapons manufacturing. And they called the area the Rocky Mountain Arsenal.
When the war effort came to an end, oil giant Shell leased the facilities to produce agricultural chemicals. Next, during the Cold War, the country made weapons at the Rocky Mountain Arsenal again. Eventually, both organizations cooperated in a thorough clean-up of the area – and they discovered something that would transform the land’s use for decades to come.
As the clean-up commenced, someone happened upon a bald eagle roost, which prompted the U.S. Fish and Wildlife Refuge to begin overseeing the wildlife at the site. In 1992 Congress bestowed the area with the title of a national wildlife refuge, which it retains today. And now, more than 330 species call the refuge home: deer, coyotes, bald eagles and bison all thrive within the park’s confines.
However, none of these species caused the 2019 bubonic plague outbreak at the Rocky Mountain Arsenal National Wildlife Refuge. No, it was something far smaller and cuter. Of course, the spread of the plague starts with disease-ridden fleas. And these insects swept into the Colordao park and started biting the area’s population of black-tailed prairie dogs.
Yes, public health officials realized that they had a problem when the Rocky Mountain Arsenal National Wildlife Refuge’s prairie dog population started to die off in droves. But it makes sense that the plague-infected fleas would attack these small mammals: like rats and mice, prairie dogs, too, are part of the order of rodentia, making them rodents, too.
To stop the spread of the plague, then, officials sprung into action. First, they shut down the Rocky Mountain Arsenal National Wildlife refuge. A statement from the U.S. Fish and Wildlife Service explained that they did so “as a precautionary measure to prioritize visitor health and safety, while also allowing staff to protect wildlife health.”
Clearly, the infected fleas could pose a problem for humans making their way through the park. The plague managed to wipe out millions of people in the past, after all. But the fleas can also attach to dogs and, while they’re not very susceptible to getting the plague, canines can carry the insects close to humans and other animals that can become infected more readily.
And so the Rocky Mountain Arsenal National Wildlife Refuge needed to eradicate the fleas to protect other animals within the park, too. Specifically, the endangered black-footed ferret calls the protected land its home – and the Colorado refuge boasts America’s second-largest population of the mammals in the wild.
The black-footed ferrets eat prairie dogs, you see, so a plague outbreak puts their numbers at risk, too. If the prairie dogs die off, so does an already-endangered species’ food source. Although a vaccine exists against the plague for black-footed ferrets, they have suffered greatly in the past when prairie dogs have contracted the disease.
Dan Tripp, who is a Colorado Parks and Wildlife researcher, told Smithsonian magazine, “Wildlife managers have struggled to recover ferrets and manage prairie dog colonies due to the devastating effects of the plague. It is our hope that use of the sylvatic plague vaccine in select areas – with the support of willing landowners – will help to limit the impact of plague to wildlife.”
Moreover, the U.S. Fish and Wildlife Service has historically made efforts to vaccinate prairie dogs against the plague. In 2016, for instance, the federal agency launched peanut-flavored vaccine pellets into South Dakota, Colorado and Montana colonies, successfully protecting up to 90 percent of the prairie dogs there.
To quell the 2019 outbreak, meanwhile, health officials have opted for a different solution: they have daubed the walls of prairie dog burrows with powdered insecticide. The thinking is that when the rodents return to their underground homes, their bodies rub up against the potent powder. And this kills the fleas attached to them, ensuring that they can’t spread.
On top of these measures, the Rocky Mountain Arsenal National Wildlife Refuge also shut down for a short period. Moreover, when the park reopened, people couldn’t access all parts of it. And instead, officials kept certain trails and areas closed where they had spotted evidence of plague infestation. Both this and the application of insecticide would help protect the disease’s spread to humans and other animals, officials hoped.
To help cope with the outbreak, certain areas of the Rocky Mountain Arsenal National Wildlife Refuge remained inaccessible throughout August 2019. And such closures have already affected those living or visiting the Denver area. For instance, officials canceled camping at a music festival at the end of the month due to roaming plague-infested prairie dogs.
In August 2019 environmental health manager Monte Deatrich told The Denver Post, “It was pretty much determined that we needed to not be careless and reckless in a way to keep people out of those areas.” Officials hung posters to warn visitors about the dangers of “an infectious disease which was once referred to as ‘The Black Death,’” but allowing camping would have put them too close to the source.
Fortunately for music lovers, rock band Phish could still have their three-day concert in the area. They just had to move their scheduled events from grass fields to paved lots. Of course, the area’s health department also urged attendees to “stay out of areas that prairie dogs inhabit” and to “avoid all contact with prairie dogs and wild rodents and to avoid fleas,” according to People magazine.
Fortunately, though, anyone who does get bitten by a plague-infested creature is in luck – at least, in comparison to those who suffered from the plague hundreds of years ago. Nowadays, you see, doctors can treat the disease with a course of antibiotics. And they have successfully reduced the mortality rate from up to 60 percent to less than 15 percent.
Of course, a doctor can’t help an infected person if they don’t seek medical attention. And so officials urged Phish festival attendees to see a physician as soon as they started exhibiting symptoms that could be linked to the plague. Antibiotics should ideally be taken within 24 hours of the first sign that a person has the disease.
It’s hard to believe that park closures and concert cancellations all come down to a colony of prairie dogs. However, considering the history of the plague – and the devastation that it has caused – it’s no surprise that officials followed such a drastic course of action. And once the insecticides and vaccines kick in, it will only be a matter of time before guests can return to all parts of the Rocky Mountain Arsenal Wildlife Refuge.