Radioactive Prairie – Stephanie Anderson

Here is what we know for sure: in the early 2000s, my mother’s left foot started to drag. She told the foot to move, and it wouldn’t. It was like a wooden foot, something unresponsive, unconnected to her brain. And then her brain seemed to forget her left leg entirely, and the leg turned wooden, too. A doctor at the Mayo Clinic in Rochester finally determined she had multiple sclerosis.

She was 50, about 20 years older than most people are when they receive such a diagnosis. But looking back, we see symptoms appearing as early as her twenties: bouts of tiredness when she couldn’t leave the bed for a day, fierce charlie horses in her legs, an ebb and flow of feeling energetic and then exhausted. Now, at 59, walking is a memory for her. Days without pain are a memory.

What happens, my family wonders, when everything becomes a memory: moving, eating, speaking, breathing. When memory itself disappears and all that is left is the wooden body.


Slowly I came to learn that the place where I grew up, western South Dakota, is home to more than 270 abandoned uranium mines and prospects, though researchers claim many hundreds more are unmarked, never recorded in any official company or government log.[i]  South Dakota was and still is one of those places where, for big companies, the rules are a bit looser, the need to document less necessary. Uranium mining occurred in northwestern South Dakota from 1954 to 1964—part of the Cold War atomic bomb campaign. And when the uranium demand slowed, the mining companies disappeared, and most didn’t bother to fill in the holes they left behind.

My mother was the first to tell me about the mines. “In the Slim Buttes,” she’d say, a cluster of pine trees and rock formations that are part of Custer National Forest, a place about twenty miles from her childhood home in the northwest corner of South Dakota. Uranium mines: abandoned, exposed, and emitting radiation, the radioactive dirt slipping into nearby streams and sliding onto adjacent pastures, blowing into the air, ingested by cattle and sheep.

She’d heard about the mines growing up, but didn’t know what to make of them, wasn’t sure she’d gotten near enough to them, though later we learned she had.

The Slim Buttes consist of massive bone-white rock formations, sometimes called “the castles” or “the battleships,” presiding over the pine trees and sandstone hills below. It’s an oasis of forest in what is otherwise a never-ending prairie, a special place where mountain lions hide away, where the air smells piney.

About an hour away from the Slim Buttes, the Cave Hills are a similar formation of steep wooded bluffs, also studded with leftover mines. Most of the Cave Hills sit on Forest Service land, others on private land. Some areas are marked with signs reading, “CAUTION: RADIATION AREA,” and other signs warning that “RADIATION LEVELS IN THIS AREA ARE ELEVATED. NO MORE THAN ONE DAY WITHIN A ONE YEAR PERIOD SHOULD BE SPENT IN THIS AREA. NO CAMPING”[ii]

The warning signs weren’t posted in the Cave Hills back then, not until residents and their livestock had already endured decades of exposure and illness.  Even today, most contaminated areas have no warning signs.

As a child and teen my mother hiked the Slim Buttes, a place with no warning signs even today. As a mother, wanting to share her favorite places with us as we grew older, she drove our family there for birthday picnics and holidays—Father’s Day, Memorial Day. Visiting the Slim Buttes, I felt as if I had entered a world so different from the grassland I grew up on. Just staring up at that many trees, watching their tops sway in the wind, was magical.[iii]

We hiked the trails, climbed as high up on the battleships as we dared, perched like eagles on the cliffs and looked down on the prairie, started campfires and roasted hotdogs and marshmallows. The sandstone mounds on the forest’s western edge sloped like giant slides. We skidded down on our bottoms, the dust covering our hands, our clothes—the dust, almost certainly radioactive; the gamma radiation present throughout the forest.


Here’s what the mining looked like: first, men assembled dirt scrapers on a suitable butte. They pared away up to 80 feet of the butte top, like scraping frosting off a cupcake, to expose the lignite coal beneath. Inside the coal was uranium.

Like a picky eater pushing unwanted food to the edge of a plate, the miners shoved the discarded hilltop—loose, highly erodible dirt called “spoils”—over the sides of the butte, then dug in to retrieve the exposed uranium ore. Though the method is technically called open pit mining, it’s more like a modified version of strip mining, only confined to a butte top.

In the Slim Buttes, miners dug trenches into the prairie sod and opened the sandstone hillsides in addition to attacking the butte tops. They left the spoils just as exposed as in the Cave Hills but in locations even closer to where people ranched and hiked—spoils that washed into streams and ponds, blended with the soil, blew into the air, became grass that fed cattle that became meat that we consumed.

The spoils contained uranium and other carcinogens and radionuclides such as arsenic, lead, radium, thorium, molybdenum, and others. The mines were left uncovered—gaping mouths, exhaling gamma radiation.[iv]


In 1991, U.S. Forest Service researchers detected gamma radiation levels of up to 100 times the background level (i.e., the “normal” level of radiation for a given area) in the North Cave Hills. Radiation exposure is linked to deadly cancers like leukemia, bone cancer, and blood cancer, as well as birth defects and autoimmune diseases like multiple sclerosis.  The site survey also found that the soil was three times more radioactive than background levels, and that nearby surface waters contained high levels of arsenic, lead, molybdenum, selenium, thorium, vanadium, and radium.[v]

Thirty-seven years after the mining began, the area remained deadly toxic. Some things, it turns out, don’t get better with time.

In 2006, a follow-up study revealed that the situation in the Cave Hills had worsened: arsenic levels in the soil were as high as 120 times background, and three different types of uranium (U-238, U-234, and U-235) were as high as 165 times background.[vi]

The surface water was similarly toxic, measuring with arsenic levels up to fifty-two times higher than background, lead up to sixty-nine times background, and uranium almost four times background.[vii]

In 2009, researchers from the U.S. Forest Service and the South Dakota School of Mines and Technology published yet another study of the Cave Hills mines noting elevated levels of uranium and arsenic in the soil and streams;[viii] and, more recently, in 2011, another study focusing specifically on the Cave Hills watershed also measured higher than normal amounts of uranium and arsenic.[ix]


Ranchers in northwestern South Dakota have borne the brunt of the exposure, because they are on the land most consistently. In a 2011 Bismarck Tribune article, Lauren Donovan reports ranchers near the Cave Hills suffered from cancers that had been “linked to uranium and arsenic exposure.”[x] One family had gallbladder issues severe enough to require gallbladder removal for every member of the family. Also, cattle grazing those hills routinely die from illnesses such as pneumonia that would be more survivable if the cattle did not have compromised immune systems. Donovan reports that one rancher feeds his cattle copper—a crucial immune system element—in amounts high enough to kill normal cows. The heavy metals his cows ingest in the grass neutralize copper as well as zinc, another immune system element, which is why the rancher feeds them otherwise lethal amounts of copper to prop up their frail immune systems.

And yet, hikers, hunters, Native Americans, and ranchers continue to access and use the land.  Government workers who maintain the land are also at risk. A risk assessment report prepared for the U.S. Forest Service identified three main “routes of exposure” for people living, working, and recreating near the Cave Hills:

  • Inhalation of contaminated windblown or suspended dusts
  • Direct contact or incidental ingestion of contaminated surface soils and sediment
  • Ingestion of contaminated meat.[xi]

For my mother, the time she spent in the Slim Buttes meant invisible radioactive dust inhabited her childhood. Later she married my father and they moved to our ranch outside of Bison, South Dakota, where she swam in the nearby Shadehill Reservoir, a waterway fed by the North and South Forks of the Grand River. Radioactive water from creeks inside the Cave Hills watershed feeds both forks. The Grand River’s South Fork lazes along just ten miles north of my parents’ ranch.

For decades my grandfather’s cattle watered at the South Fork; their calves eventually became meat that went into the food supply, some of which appeared on my parents’ table.


The Cave Hills command the most scientific attention, the most thorough studies. Those butte top mines are dramatic and big; one mine spans 150 acres. Because of their visibility, some parts of the Cave Hills, such as a place called Riley Pass, have been cleaned up.[xii] Good news, no doubt. But the Slim Buttes area—where members of my mother’s childhood church gathered for picnics, where people still camp and hike and hunt and ranch—has always been just as toxic and remains so, with only a handful of studies done to assess the effects. Yet the available research reveals just how dangerous the Slim Buttes are.

A 2003 study recorded uranium levels of 1,704 times the background level at one Slim Buttes mine. By comparison, in the same report the highest uranium reading in the Cave Hills was 366 times background. Other locations in the Slim Buttes came in lower, around twenty times background—not as high as the 1,704 times background, but still dangerous.[xiii]

If the government warns people not to spend more than one day a year in the Cave Hills, then it stands to reason that the same cautions should apply to the Slim Buttes. But the ranchers keep grazing their cattle. Families keep unpacking Sunday picnics. Hikers and hunters keep exploring the radioactive forest. My mother spent dozens of days a year there as a child and teen, during a time when her young body was developing and was most vulnerable to radiation. She returned again and again as an adult. She breathed the air, touched the soil. She wandered near some of those mines where the gamma radiation is strongest.


Prairie City, a village in northwestern South Dakota about twenty miles from the Slim Buttes, is home to just twenty-three people. A hundred or so more people live on the surrounding farms and ranches, scattered miles apart. When my mother was growing up outside of Prairie City in the 1960s and 70s, those population numbers were much higher. The town had a grocery store, a school, a post office, a bar, a gas station. Now it’s just a cluster of homes and a run-down church. The nearest movie theater is forty miles away, the nearest airport is 150 miles away. This is one of the most desolate, sparsely populated areas in an already desolate and sparsely populated state. It’s also an area overflowing with what seems like an unusually high proportion of sick people.

According to a Healthline infographics report, in northern states like South Dakota, the MS rate is 110-140 cases per 100,000 people.[xiv] Shrink the scale down, and you’re looking at eleven to fourteen cases per 10,000 people. But in my mother’s county of around 3,000 people, she can name about a dozen people with MS, and these are just the folks she knows about. Many of them are people she went to grade school with in Prairie City or people who lived or continue to live near the Slim Buttes. Just from the rough numbers, it not unreasonable to suggest that my home county’s MS rate could be three to four times the national average.

In the next county over, where the Slim Buttes and Cave Hills are located and the population is around 1,200 people, there are likely others with MS. The problem is that no one knows or tracks the whereabouts of people with MS—not here or nationwide. MS is not considered an infectious disease and therefore is not “reportable” by the federal government. There is no national MS registry.[xv] The Multiple Sclerosis Foundation estimates that 400,000 Americans have MS, but they don’t know for certain.[xvi]

The National Multiple Sclerosis Society has identified a few “MS clusters” in the United States—areas with abnormally high MS rates, all of them in the Midwest.[xvii] While the evidence for an “MS cluster” in western South Dakota is anecdotal at this point, the general feeling back home is that MS is fairly common. Too common.

“There is so much MS in this country,” Phil Jerde, a man who lives near the Slim Buttes, told me.  He shared his concerns and admitted that he and his family of ten children only drink filtered, bottled water because he believes there could be a connection between MS and the water coming from the local wells. Given the large number of people with MS in this rural community, Phil believes that the precaution of buying bottled water is worth the extra expense.

Proving a link between my mother’s MS and her radiation exposure is difficult, just as it is for others in the area suffering from this disease or other radiation-related cancers. Most of the exposure occurred decades ago; it would be impossible to recount every time my mother touched radioactive soil or ingested toxic meat or inhaled tainted air or swam in contaminated water. Also, so many people have left the region.  There’s no data that details exactly how many people are ill and what diseases or birth defects they have, or how many live near abandoned mines, or whether other causes might explain their illnesses.

A lot of people in the area are sick, but a lot of people aren’t, too—people who may well have received equal or higher amounts of radiation. MS has no known cause, after all. Maybe the processed meats my mother ate are to blame. She was raised on the new-fangled processed foods that appeared in the 60s and 70s, and those eating habits continued into adulthood, although she’s improved her diet since her diagnosis. She also smoked for about ten years. Perhaps lifestyle choices contributed to her disease.

But even if radiation isn’t causing MS and cancer in western South Dakota, the ongoing injustice of exposure remains. An article in the Rapid City Journal confirms that Kerr-McGee, the corporation that once owned some of the Cave Hills mines, “fraudulently moved assets around to evade debts and liability for environmental clean-up.”[xviii] The corporation cared more about saving its skin (and delivering profits to shareholders) than about the people, especially the rural poor living near its mines. Kerr-McGee Corp. exposed generations of ranchers and farmers to radiation, most of them barely eking out a living on the dry plains, just as Monsanto poisoned the rural, mostly African-American town of Anniston, Alabama, with cancer-causing PCBs (polychlorinated biphenyls) that leaked from its agrochemical plant into the community’s water and soil[xix]. This social injustice mirrors the way that mega-corporations force communities in the Midwest to endure the toxic stench of concentrated animal feeding operations (CAFOs)[xx]. It feels much like the way Big Packing exploited immigrant workers in Chicago in the early 1900s, and the way that corporate farms in places like Florida and California continue to exploit cheap migrant labor. It’s the same way that utility giant Pacific Gas and Electric Co. killed residents of Hinkley, California, through contaminated water, a case made famous by the film Erin Brokovich.[xxi]

In all these cases, the lesson is clear:  poor lives are expendable or at least unimportant, in the larger calculations of capitalism. The human cost of business cannot be quantified on a profit and loss sheet, and so is ignored or forgotten completely. Poor people don’t have the means to sue. It’s a question of power—who has it, who lacks it, who can buy it, who is born with it.

This is absurd, I think from my Florida home where I spend my time piecing together new facts about a place I thought I knew inside and out. How can entire buttes and hillsides have been left to exude deadly radiation for more than sixty years?

And there’s this: I spent eighteen years in this toxic area. As a child, I drank the water, ate the food, played in the Slim Buttes, and swam in the reservoirs. How much radiation did my body absorb? And what should I make of the fact that exposed people like my parents have a higher likelihood of bearing children, not only with birth defects, but also with diseases that manifest later in life?

My mother’s MS wasn’t diagnosed until she was 50, though her symptoms appeared earlier. I am 31. Perhaps it is only a matter of time before I, too, become a product of the radioactive prairie.


[i] Lilian Jones Jarding, “Uranium Activities’ Impacts on Lakota Territory,” Indigenous Policy Journal 22.2, Fall 2011, 4. The statistic of 270 abandoned uranium mines and prospects doesn’t include the thousands of exploratory wells pock-marking the southwestern portion of the state, wells that invite uranium to seep into the groundwater.

[ii] View a photo of these signs published in 2014 in the Rapid City Journal here:

[iii] View photos of the Slim Buttes published in 2013 in South Dakota Magazine here:

[iv] Information about open pit mining and spoils is from Jarding, “Uranium Activities’ Impacts,” 1-3.

[v] Jarding, “Uranium Activities’ Impacts,” 1-3 and 6.

[vi] Portage Environmental, Inc., “Final Human Health and Ecological Risk Assessment for the Riley Pass Uranium Mines in Harding County, South Dakota,” Prepared for the USDA Forest Service May 2006, 2-17.

[vii] Portage, “Human Health and Ecological Risk,” 2-18.

[viii] Gregory G. Kipp, James J. Stone, and Larry D. Stetler, “Arsenic and uranium transport in sediments near abandoned uranium mines in Harding County, South Dakota,” Applied Geochemistry 24, 2009.

[ix] Lance N. Larson and James J. Stone, “Sediment-bound Arsenic and Uranium Within the Bowman–Haley Reservoir, North Dakota,” Water, Air, & Soil Pollution 219, 2011.

[x] Lauren Donovan, “For some, mining clean up at Cave Hills comes too late, Bismarck Tribune, May 15, 2011. Available online here:

[xi] Portage, “Human Health and Ecological Risk,” vi.

[xii] Limited cleanup has been done in the Cave Hills, but not the Slim Buttes. For more information about cleanup in the Cave Hills, see Seth Tupper, “Righting a Wrong at Riley Pass: After 51 years, mine cleanup finally begins,” Rapid City Journal, July 31, 2016. Available online here:

[xiii] Michael D. Kerschen et. al., “Abandoned-Inactive Mines on Custer National Forest-Administered Land,” Montana Bureau of Mines and Geology Abandoned-Inactive Mines Program, Open-File Report MBMG 421, 2003, 69.

[xiv] Ann Pietrangelo and Valencia Higuera, “Multiple Sclerosis by the Numbers: Facts, Statistics, and You,”, 2015,

[xv] “Who Gets MS? (Epidemiology),” National MS Society,

[xvi] Pietrangelo and Higuera, “Multiple Sclerosis by the Numbers: Facts, Statistics, and You.”

[xvii] “Clusters,” National MS Society,

[xviii] Joe O’Sullivan, “Settlement gives $179 million to clean up abandoned uranium mine in Harding County,” Rapid City Journal, June 1, 2014. Available online at:

[xix] Sean, O’Hagan, “Toxic Neighbor: Monsanto and the Poisoned Town”

[xx] Leah Douglas, Mother Jones.  “Large Scale Animal Agriculture is Threatening Rural Communities.  Congress is About to Make it Worse.”

[xxi] Steinberg, Jim.  San Bernardino Sun.  “Milestone reached in cleanup of polluted Hinkley water made famous in ‘Erin Brockovich’.”

Author Bio: Stephanie Anderson holds an MFA from Florida Atlantic University, where she currently serves as an Instructor of English. Her work has appeared in The Rumpus, The Pinch, Hotel Amerika, Midwestern Gothic, Grist Journal, The Chronicle Review, Sweet, and others. Stephanie’s debut book, One Size Fits None: A Farm Girl’s Search for the Promise of Regenerative Agriculture, was released in January 2019 with University of Nebraska Press. She lives in Boca Raton, Florida.

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