This story originally appeared in the Heat issue of Popular Science. Current subscribers can access the whole digital edition here, or click here to subscribe.

On a given day in the area around Moab, Utah, visitors may view snowcapped mountains while gazing through a red-rock-desert arch that curves above a Grand-rivaling canyon. Or they might fish a river and then scale sandstone cliffs. Or perhaps they’ll wander a pine forest in the morning and uncover a dinosaur fossil after lunch.

“There’s no one that’s seen it all,” says Russell von Koch, speaking of the vast and wild lands around the town he’s lived in for more than 30 years. He pauses, then says, “There are many out trying.”

And he does mean “many.” Moab, with a population of just over 5,000, is a capital-D Destination for outdoor enthusiasts. Three million people visit every year. Some go because it’s the gateway to both Canyonlands and Arches national parks, the latter of which regularly announces on social media that it’s at capacity. Others come for the less regulated or less trafficked public lands: national forest, state parks, and 1.8 million acres overseen by the Bureau of Land Management’s (BLM) Moab Field Office. Von Koch worked for the BLM for three decades, in large part as a recreation manager for the Moab area, developing amenities like campgrounds and bike paths. “Almost anything that’s outside the national parks, I probably had some role in the creation of the facilities,” he says.

Von Koch understands the strong force of the place. “The areas around Moab have more scenic diversity than any place I’ve ever been in the world,” he says.

Because of this, Moab attracts ATV enthusiasts who power down trails, Jeep drivers who slink along canyon roads, hikers who traipse tricky paths, and mountain bikers who crank their tires over the rocks. The town’s Main Street is home to everything from MOYO (frozen yogurt) to the Moab Brewery to Pagan Mountaineering.

In the middle of that Patagonia-saturated stretch, though, you’ll also find a structure labeled Uranium Building. Once full of offices, today it also houses a novelty T-shirt store. But it was constructed and named during the city’s first boom, in the 1950s—the one that put it on the map.

Moab, see, was home to the Atlas Uranium Mill, one of the most productive processing facilities for the raw radioactive ore. The site was one of a couple dozen in the US that transformed the stuff into the refined material that seeded power plants and weapons during Cold War times.

The taint on the land, and harms to human health, were the effects of shortsighted thinking. They were born of a perceived national security need, a lack of understanding, and a lack of regulation.

Geoffrey Fettus, National Resources Defense Council

The facility also transformed Moab from a sleepy town into a wide-awake city. But when demand for element 92 waned and the plant was shuttered in 1984, a dangerous environmental legacy remained: an 80-foot-tall, 16-million-ton mound of radioactive (colloquially “hot”) waste. The heap contains radium, which uranium produces when it decays. Radium’s half-life—how long it takes for half of a given sample to decay—is 1,600 years. But the real problem is that it becomes radon, a gas that can increase humans’ risk of cancer when inhaled. The waste also transmits radioactive material, metals, and other unwanted substances into the groundwater and the Colorado River, harming wildlife. All just three miles from the city center.

Some call it “the Pile” or “the Eyesore.”

Since 2003, the US Department of Energy (DOE)—steward of the nation’s nuclear weapons and charged with addressing environmental and atomic challenges—has been working to clean up the mess. Across the West, the DOE has remediated 18 uranium processing sites in the same category as Moab’s, their own piles ranging from 60,000 to 4.6 million cubic yards of material. The only ones left are a disposal site in Grand Junction, Colorado, and Moab, which has the dubious distinction of having to deal with 12 million cubic yards of waste. “But that will end,” von Koch says. “And so what happens next?”

[Related: Everything you need to know about uranium.]

What-next is, in fact, von Koch’s job. As chair of Moab’s Site Futures Committee, he coordinates an effort to plan potential development of the nearly 480-acre federally owned property. It’s the kind of real estate—waterfront, next to a national park—that would sell for unimaginable millions if it were listed (which it won’t be). Von Koch is preparing for the event that the DOE will simply turn over the land to local government after the agency finishes scrubbing the site. The plan detailing what might then become of it has a straightforward title: “After the Pile.”

Remediating the Atlas property—​an endeavor called the Moab Uranium Mill Tailings Remedial Action (UMTRA) project—is the job of a second Russell, Russell McCallister, the DOE’s cleanup director. “That site’s been there for a long, long time,” McCallister says. “Most everybody in Moab, to a person, wants it gone.” His work’s an industrial version of the “Leave no trace” motto, which urges adventurers to minimize their impact on the land.

Or, more accurately, remove the trace of whoever came before. That’s McCallister’s specialty. He spent six years, for instance, dealing with the mess left at a former nuclear weapons factory in Colorado called Rocky Flats, which had been so poorly run that the FBI raided it in the late 1980s for environmental violations—like illegally burning hazardous waste under cover of night. McCallister’s team shortened the estimated detox time by nearly 70 years.

Three years into his UMTRA tenure, Moab’s countdown clock has gone from a projected finish time of 2034 to one of 2029. He hopes he can move it to 2027, maybe even 2025, by speeding up the pace while maintaining safety (no one’s been hurt on-site in more than four years).

What came before at Moab traces back to the beginning of the Cold War, when the Atomic Energy Commission—the DOE’s predecessor—was desperate for uranium to fuel nuclear weapons projects. It mounted a public relations campaign to convince people to go prospecting. “‘We’ll buy any uranium you guys got, and we’re going to pay you top dollar,’” says McCallister, describing the government’s pitch.

In the early 1950s this lit a spark for geologist Charlie Steen, who took a Jeep and his family to a tar-paper shack outside Moab. In July 1952, he broke his drill on a coal-like core made of a mineral he didn’t recognize. “He was down to his last dime,” says McCallister, when Steen drove to a gas station, hoping to get some fuel on credit.

He brought a chunk of the dark stuff with him, and the store’s owner happened to be Geiger-counting some samples. Steen, mostly in jest, stuck his find up to the instrument. “It went off the charts,” McCallister says. Steen had found a deposit of pitchblende, which today geologists call uraninite, a rich and radioactive ore.

In fact, it turned out to be the largest high-grade uranium deposit in the US, around 3,000 feet long, 800 feet wide, and up to 35 feet thick. Soon, Steen developed the claim into a mine called Mi Vida: “My Life.” He became known as the King of Uranium. And Moab, once a slow farming community, became the self-styled Uranium Capital of the World. Hearing of his cache, would-be discoverers descended, ballooning the population from 1,200 to 4,600 within a few years. Locals started renting their yards to campers. Water grew short. Schoolkids had to learn in shifts.

Steen had hit upon the largest high-grade uranium deposit in the US, around 3,000 feet long, 800 feet wide, and up to 35 feet thick. He became known as the King of Uranium. And Moab, once a slow farming community, became the Uranium Capital of the World.

Straight out of the earth, uranium ore isn’t much good: It needs to be processed into a concentrated form called yellowcake, which resembles fancy mineral makeup. To make the stuff, Steen established a mill called the Uranium Reduction Company on the banks of the Colorado River. “Trucks and trucks and trucks of this material were rolling through the streets,” says McCallister.

In processing, machines crush the ore, then mix in acid or an alkaline solution, which dissolves the uranium, leaving the undesirable rock and other minerals.

Those sandy leftovers are called tailings, and the mill pumped them into a pond on the west side of the property. In 1962, Steen sold the mill to a corporation called Atlas. The facility continued to churn through 1,400 tons of ore every day, fueling weapons through about 1970 and power plants after that. Over decades, the waste piled up. It was full of heavy metals and radium, a by-product of uranium’s decay. Radium itself transmutes into radon, which gives birth to radioactive particulates. “Those can be inhaled, get caught in your lungs, and radiate people for a long time,” says McCallister, increasing the risk of cancer.

The problem wasn’t just the radiation that the pile lofted upward. Rainwater filtered through the material into the soil, then the groundwater, which leached into the Colorado River, contaminating it with substances like ammonia. When the DOE released its environmental analysis in 2005, ammonia in the part of the river nearest the tailings pile was more than 10 times the acceptable amount, killing young, already endangered fish. The Moab mill, says Geoffrey Fettus, senior attorney at the Natural Resources Defense Council, “is a dreadful relic that shows the scope and scale of the kinds of messes that we can make if we don’t look forward properly and with a clear eye.”

The taint on the land, and harms to human health, were the effects of shortsighted thinking, Fettus points out. They were born of a perceived national security need, a lack of understanding, and a lack of regulation. “That was something the country started to come to grips with in the ’60s and ’70s,” he continues.

[Related: The US military has a torrid history with nuclear reactors.]

In 1978, Congress passed the Uranium Mill Tailings Radiation Control Act, legislation intended to spur the cleanup of inactive processing sites. Five years later, the Environmental Protection Agency enacted standards to improve such facilities from the start. But even then, says Fettus, radioactivity wasn’t in hazardous waste laws—and today it is treated separately. “There’s none of that straightforward regulatory control,” he says.

Contamination appears across the Intermountain West, where extraction went boom and bust, leaving behind abandoned mines and mills, including Atlas’. Starting in the late ’80s, the company used soil to place a temporary cover over the tailings. The pile didn’t present an immediate, acute risk of leaking or harming health, but it required a permanent cover and better barrier to block it from leaching into the water. Atlas had plans for that but went bankrupt in 1998. Eventually, in 2001, the pile became the DOE’s problem.

The DOE got to work in 2003. The agency installed wells to extract polluted groundwater, sent it to a storage tank, and sprayed it on the tailings pile to control the radioactive dust. It dug other wells to divert clean water from the Colorado River and inject it into the surrounding soil to dilute the contaminants. Since the start of the project, the effort has stopped more than 955,000 pounds of ammonia and 5,300 pounds of uranium from slipping into the waterway.

For years, officials considered what else to do, and how. DOE officials debated burying the pile under a special cover on the original site or moving it to one of several drier and less populated places nearby. After taking 1,600 public comments and doing an environmental impact analysis, they settled on relocating the refuse around 30 miles up the road, to a disposal cell in a spot called Crescent Junction, which exists mostly as “the place where one exits I-70 to get to Moab.” A literal junction.

Department of Energy workers dig up the pile of waste at the Atlas uranium mill. Russell von Koch

Since 2009, workers have transferred 11.5 million tons of waste—more than 70 percent of what was there to start with. Today, they’re working on the last portion. They dig out the tailings with heavy equipment and spread them out in open “drying beds” (which poses no greater risk than already exists at the site). Once the residue has shed its water weight, it goes into steel containers and gets loaded onto a train to nowheresville. Since he took over in 2017, McCallister has doubled daily trips from two to four and added more cars, pushing up the projected finish line.

The Moab site appears pretty unobtrusive unless you already know what’s going on. Sure, there’s a giant red-dirt scar on the landscape, with trucks wheeling toward railcars. But that looks like any number of active extraction-industry spots in Utah for metals, natural gas, oil, and coal. At one entrance, a chain-link and barbed-wire fence lines a public pull-off, a small roadside area with weeds growing through the cracks. A yellow-and-magenta biohazard sign hangs next to a yellow one that says “No Trespassing, by order of the United States Department of Energy.” Beside it, there’s a kiosk like you’d find at a trailhead, with a single sheet of paper pinned to corkboard, detailing the history and background of the Moab UMTRA project.

Because the signage is low-key, people do sometimes end up accidental trespassers, pulling campers into the employee entrance, wanting to use the bathroom (no), then finding they can’t turn around. Two years ago, tourists followed their GPS in, got around the security guard, and had to be escorted out. Being on-site for short periods isn’t hazardous—it doesn’t raise radiation exposure much above background. In part to avoid unexpected visits from the public, though, McCallister has struggled with whether to be more upfront with the branding. But attention is complicated. “Do you advertise that you’re a DOE site cleaning up radioactive material?” he asks. That might draw unsavory curiosity, purposeful trespassers, souvenir seekers, angry activists. “Or do you just leave that little sign out there that nobody seems to notice?”

The branding at the disposal area outside Crescent Junction is subtler. A small black-and-white sign at the entrance to the access road says simply, “DOE SITE,” pointing toward an open gate that warns against trespassing. More barbed wire defines the rest of the boundary, with the same yellow signs as at Moab. Still, if you climb the badlanded hill adjacent to the property and look down, you can see a long line of train cars and hear their clanking. In the midst of the distant action, a giant dark L marks the land, abutted by a few scraped-away rectangles. It might be a tilled field or a gravel pit. Very little indicates it’s the final resting place for radioactive waste.

Few people are around to notice at all. In Crescent Junction, there are two houses and a gas station called Jackass Joe’s.

Painted in neon green, it’s designed to do the opposite of the DOE sites: get your attention. Giant signs above the pumps proclaim “Jackass Joe’s UFO Jerky” and “Twilight Zone.” Nearby, a third one says “Welcome to Our World” around a painted flying saucer, although there aren’t any more sightings here than in any other random spot in the West. Yet another promises that customers may purchase “Food & Sandwiches & Cheap Ass Microwave Shit.” There’s a Scooby-Doo Mystery Machine parked out front.

Government barriers warn off residents and adventurers. Sarah Scoles

It’s a good distraction from what’s going on a mile or so away. There, trucks take tailings from the train to the disposal cell, an excavated area that, once finished, will be a mile long and nearly half a mile wide. The waste will be buried 25 feet down. But first, a dozer spreads the material and a roller squishes it. Once all of it is in place, workers will create a cap to keep contaminants from leaking up or down. The permanent covering will be 9 feet deep, comprising several different layers of soil and rock—most importantly, radon-blocking shale.

McCallister actually wants to change the cap’s design. Its top layer—straight rock, excavated from nearby Fremont Junction—was the Nuclear Regulatory Commission norm 20 years ago. “Now those covers are failing,” he says. Water seeps through and doesn’t evaporate, so it could eventually find its way to the underground supply.

A newer type of top layer—a mix of rock and soil—would allow water to permeate only about a foot and then evaporate. But the Nuclear Regulatory Commission won’t approve the design until the end of 2023. McCallister plans to forge ahead with preparations anyway. “It’s the right thing to do,” he says, adding it’s a gamble: He will have to go back to the old idea if the commission says so.

Whatever the top is made of, the invisible contaminants should stay trapped, barely raising the radiation level at Jackass Joe’s, when the project is finished. In 2020, the total annual gamma radiation at the home nearest the site was about 26 percent above Crescent Junction’s natural buzz.

When the project is finished” is a milestone von Koch spends a lot of time considering. “Everyone wants to get it done,” he says, “to get it done right.” He actually volunteered to lead the Site Futures Committee back in 2013 to plan for The Aftertimes, because he realized his experience with the Bureau of Land Management would help. He’s a busy guy, though: He’s also the community’s liaison with the Department of Energy and a staff member for the Moab Tailings Project Steering Committee. As with the campgrounds and benches, if there’s a tailings project in Moab, von Koch has probably touched it.

As he sees it, relations between the project and the community are pretty smooth, at least for a giant radioactive government scheme. Still, the work hasn’t been without hiccups. In 2014, there was a rockslide (enter: a brick wall to block future spillage). In 2016, a cartage truck flipped. Probably the biggest friction point between the UMTRA project and the city is dust—radioactive powder that blows around with the wind. “My solution to the dust problem is to get rid of the pile,” says McCallister.

[Related: Why water restrictions from the Colorado River matter.]

Von Koch wants that too, so he and other residents can realize their hopes for the site if the DOE turns it over to the local government. That happened just up the interstate, in Colorado’s Grand Junction, where a former processing site became Las Colonias Park, owned by the city, which added an amphitheater, skate park, and boat ramp to the site. Places like these continue to be monitored by the DOE, to make sure their remaining releases are acceptable.

Laid out in 2018, Moab’s latest plan is ambitious. Where there’s now a hump of radium and dust, the community envisions an event center that could host car shows and concerts. At an eatery area, food trucks could park. People might recreate on playgrounds, do pullups at fitness stations. There could be an ice rink in the winter that becomes a reflecting pond in the summer. Climbing walls. Slacklines. A swimming pool. A transit center shuttling people out to Arches, downtown Moab, or popular trailheads. Maybe someday a passenger train could travel along the spur that now carries the tailings.

Lest anyone forget, though, informational signs would tell the story of the site, and a memorial would stand “to those individuals and families affected by the exploration for uranium and its mining, milling, and remediation on the Colorado Plateau.” That process often exploited Indigenous miners, thousands of whom went to work for low pay in dangerous conditions.

Hot waste from the Atlas mill will be laid to rest at this site in Crescent Junction, Utah. Courtesy US Department of Energy

In this vision, the mill would transmute into something wholly different, just as uranium itself does, in a process that is the exact opposite of decay.

Still, traces of the old identity will remain. Despite whatever playgrounds and snack shacks appear, or which earthen mixture tops the disposal cell, these marks will signal that Moab was once the Uranium Capital of the World.

It’s fitting; the Moab region reveals its past more easily than most places. Geologic strata lie exposed. Canyons snaking across the landscape display water’s long-ago flow. One can mentally re-place piles of fallen rock right back into the cliff from which they came.

A few miles up the road from Crescent Junction, petroglyphs from almost 2,000 years ago etch the cliffs near the roofless buildings of a tiny mining town abandoned in the middle of the last century. In this extremely dry climate, even footprints stick around.

Very little, here, has ever left no trace at all.

This story originally appeared in the Heat issue of Popular Science. Current subscribers can access the whole digital edition here, or click here to subscribe.