Near the end of a washboard gravel road climbing uphill about five miles off Interstate 70 at Parachute, it feels a bit incredulous that in 1969 a 40-kiloton nuclear bomb detonated directly underfoot — yielding a blast with nearly three times the power of the bomb that leveled Hiroshima and killed almost half of its 300,000 residents.
Today, the landscape above Garfield County’s Battlement Mesa community is peaceful and sparsely populated.
Dense forests flank the road ending at a White River National Forest trailhead that takes hikers to sweeping views of the plateaus towering over both sides of the Colorado River.
The only visible signs of the massive underground nuclear explosion — conducted as an experiment to see whether the bombs that had changed warfare and geopolitics could also be used to extract oil and gas — are a small bronze plaque installed in 1976 atop a cement-plugged well, and a more recent explanatory signboard headlined “Project Rulison: A controversial test that shook Colorado.”
It wasn’t the only nuclear explosion aligned with oil and gas extraction set off in the region. On May 17, 1973, about 35 miles northwest of Rifle in Rio Blanco County, three 33-ton nuclear bombs were detonated simultaneously underground at different depths, totaling more than 90 kilotons of explosive force.
The Project Rio Blanco site also has a small historical marker, located on a more isolated expanse of cattle grazing land off County Road 29.
The Rulison test — conducted at a depth of 8,425 feet — was the deepest subterranean nuclear-bomb detonation conducted in U.S. history.
Shortly after 3 p.m. on Sept. 10, 1969, and about three seconds after the end of a dramatic countdown, “The whole ground buckled,” described Jay Cowan, who was protesting the bomb from a press and VIP tent set up several miles away and across the Colorado River from the detonation site, joined by about 50 other protesters from Aspen.
Garfield County Sheriff’s Office deputies had told the protesters to “stay the hell out of the tent,” Cowan said. “Which to us sounded like a challenge.”
Cowan, who was 17 at the time, compared the blast’s effect to standing on a freestanding dock when a big wake passes under.
The explosion registered 5.5 on the Richter scale.
The worst fears — a dam break at Harvey Gap Reservoir or Ruedi Reservoir, crumbling of railways, roadways and other infrastructure, and the immediate release of above-ground radiation — were not realized.
About 35 families living within five miles of the blast had been evacuated and coal miners had been ordered above ground.
“Some of my friends’ parents didn’t think we should go,” Cowan said. “Because if it vented — we were that close.”
Cowan described seeing rocks cascading down the faces of far-off cliffs.
In the hills above the blast site, a pair of protesters from the Front Range lay on their stomachs, bracing themselves with their arms bent at the elbows.
Their presence inside the quarantine zone, which encompassed a five-mile radius around the blast site, did not — as hoped — stop the experiment.
Judy Haas, a then-16-year-old sophomore at Aspen High School, attended the protest with Cowan. She described “a massive cloud of dust” rising from the earth as far as the eye could see.
There was a collective state of shock among observers, Cowan recalled, and a 30-second post-detonation silence where the only sound heard was a baby crying. “It was eerie. … Everyone was kind of somber.”
For Haas, who just days before had pleaded with representatives from Austral Oil Co. and the U.S. Atomic Energy Commission (AEC) at a community meeting in Aspen to stop the test, the overwhelming feeling was one of disillusionment.
“We asked them not to detonate the bomb,” she said from her home in Telluride, more than a half-century later. “Their response was essentially they were going to do what they were going to do — and that was it. We were all really sad that we hadn’t been heard, that we don’t have a voice.”
Haas, now an artist with her own gallery in Telluride, helped late legendary Aspen artist Tom Benton silkscreen and distribute his iconic signs at the 1969 protest, declaring, “Stop the atomic blast. No contamination without representation.”
Deep underground, the blast’s intense heat vaporized rock, creating a subterranean cavity about 150 feet wide and 350 feet deep encased in a glasslike seal, according to a U.S. Department of Energy (DOE) fact sheet about the project. Fractured rock then collapsed into it.
The Rulison and Rio Blanco sites are not just a bizarre vestige of Colorado history.
They continue to be monitored — and will be in “perpetuity” — by the DOE’s Office of Legacy Management, which works to ensure that whatever radioactive nuclides are still trapped underground remain there, especially as with every natural gas boom industry operators look to drill closer to the detonation sites.
“Residual radioactive contamination remains at the detonation depths of each site,” Office of Legacy Management spokesperson Christine A. Jost wrote in a Dec. 20 email, responding to questions from Aspen Journalism.
Since testing began in the 1970s, “The sampling of natural gas wells, surface water and shallow groundwater wells have not detected any Rulison or Rio Blanco test-related contaminants,” according to Jost.
Yet some observers remain concerned that modern horizontal drilling and fracking technologies have increased the risk that the entombed radioactive material may be disturbed, and skepticism persists that the flaring of contaminated natural gas after the Rulison test had harmful effects.
Nuclear testing, banned by 186 other countries in 1996, has also not been relegated to the past, with President Donald Trump on Oct. 30, 2025 writing in a social media post, “Because of other countries testing programs, I have instructed the Department of War to start testing our Nuclear Weapons on an equal basis. That process will begin immediately.”
Although “that process” did not begin immediately and other nations are not currently openly testing nukes (and it is the DOE that carries out nuclear tests), the statement indicates the prospect of nuclear testing is, at a minimum, alive in the mind of the only person in the country with the sole authority to order the use of nuclear weapons without requiring approval from any other individual or agency.
Conversations have also renewed about bringing nuclear power back to Colorado to replace soon-to-retire coal plants. In April, Gov. Jared Polis signed a new bill defining nuclear energy as a “clean energy resource.”
On Jan. 6, the DOE announced it would award $2.7 billion in funding to three companies with the goal of increasing domestic uranium enrichment over the next decade.
On Feb. 5, the New Strategic Arms Reduction Treaty expired, and with it any remaining legally binding limits on massive nuclear arsenals held by the United States and Russia.
A Feb. 9 article in The New York Times states, “In the five days since the last remaining nuclear treaty between the United States and Russia expired, statements by administration officials have made two things clear: Washington is actively weighing the deployment of more nuclear weapons, and it is also likely to conduct a nuclear test of some kind.”
Although the full environmental impacts from the Rulison and Rio Blanco tests remain enigmatic, the experiments launched a legacy of environmental activism, including a citizens initiative, which was passed by a wide margin in 1974, requiring a statewide vote before anyone else can test nukes on or under Colorado ground — making it the only state in the nation with such a provision.
Nuclear stockpile seeks peaceful purpose
The stated goal of Project Rulison for the AEC, now the DOE, and industry partners Austral Oil and CER Geonuclear Corp. was to facilitate the extraction of natural gas from the prolific but hard-to-penetrate Williams Fork Formation in the Piceance Basin.
With the exception that the AEC partnered with CER Geonuclear and Continental Oil Co. (Conoco), the purpose of Project Rio Blanco was the same: to “stimulate the flow of natural gas in low-permeability geologic formations,” according to the DOE’s Rio Blanco fact sheet.
Modern fracking technology had not yet come into play, and the country was energy-hungry.
“They found that the Mesaverde formation in the Rulison field of west-central Colorado appeared to be a suitable area for nuclear stimulation since, from known drilling and testing data, the underlying reservoir rocks contained an estimated 8 trillion cubic feet of natural gas at depths ranging from 6,200 to 8,700 feet beneath some 60,000 acres,” according to the Rulison Manager’s Report written in 1973 and released to the public in 2007. “The permeability of the reservoir rocks is so low that conventional production stimulation methods seemed impractical and uneconomical.”
The idea was to shatter the rock surrounding the blast, creating far-reaching fissures to stimulate the flow of oil and gas to then collect it in the massive underground cavern left behind by the nuclear explosion. Another reentry well would then need to be drilled to pump and test the gas for radioactivity.
“The procedure lacked comprehensive postshot plans,” according to the “conclusions” in the manager’s report. “But it was agreed that the Rulison Technical Committee would base their plans on results from the detonation.”
Faced with an oversupply of nuclear weapons stockpiled during the height of the Cold War, a contingent of scientists and politicians in the United States began dreaming of the “peaceful” possibilities of thermonuclear detonations, including atomic bomb creator Edward Teller, who attended the Rulison event.
“War was obviously out of the question, but one line of thinking emerged: Could these weapons, designed to obliterate any trace of civilization, be repurposed for peaceful uses?” wrote Zachary Thompson in his article on the history of Rulison published in the University of Colorado Denver’s May 2025 edition of the Historical Studies Journal.
Thus was born the “Atoms for Peace” campaign and Project Plowshare, during which the U.S. government conducted 27 nuclear tests with 35 individual explosions from 1957 to 1973, including the two nuclear fracking tests in Colorado.
The initiative was named for the Biblical verse from the Book of Isaiah: “They will beat their swords into plowshares and their spears into pruning hooks. Nation will not take up sword against nation, nor will they train for war anymore.”
The Rulison test was watched with bated breath — including by President Richard Nixon — and was seen as a potential precursor for a fantastical future using nukes to blast a new Panama Canal; cut through mountains in California to make way for roads and railroads; redirect rivers; flood deserts; trigger small earthquakes to prevent larger ones; and create a new deepwater harbor in Alaska.
“Such ideas may seem preposterous to those raised in the age of environmentalism, but to Teller and his colleagues, nuclear weapons were just another tool to put to use. Plowshare scientists sought out those uses with an almost reckless abandon,” Patrick H. Shea wrote in a 2024 Science History Institute article.
“Plowshare scientists looked at the natural world as if it were a piece of clay waiting to be sculpted by nuclear tools,” Shea wrote. “As the ‘father of the hydrogen bomb,’ Edward Teller, remarked, ‘If your mountain is not in the right place, drop us a card.’”
Nuclear fracking fails
Project Rio Blanco was the nation’s third and final experiment in nuclear fracking.
Including the initial Project Gasbuggy test in 1967 in northern New Mexico, the three endeavors cost the U.S. government at the time about $82 million (about $796 million today).
A fourth nuclear test using a 50-kiloton bomb to fracture deep oil-shale deposits, Project Bronco, was proposed in Rio Blanco County but never executed.
The three tests were abject failures in terms of commercial natural-gas production. There was a technical success in that the blasts did significantly stimulate gas flow. However, that nuclear-released gas came with an insurmountable caveat.
The gas was contaminated with various radionuclides, including tritium, krypton 85 and carbon-14 at both Rulison and Gasbuggy, and cesium-137 and strontium-90 at Rio Blanco.
“AEC spokesmen say that the Gasbuggy blast was designed mainly as an experiment to measure the resulting radiation, not necessarily to produce commercially usable natural gas.” according to a 1969 article in Time magazine. “Because of new safeguards, they predict Rulison’s radiation will be much lower than Gasbuggy’s.”
At Rulison, even after 107 days over seven months spent flaring off 455 million cubic feet of radiated natural gas into the atmosphere, the radioactive elements did not dilute enough to make the gas marketable.
According to a 1970 New York Times article, “When a natural resource such as the natural gas in Project Gasbuggy is in intimate contact with the radioactive byproducts of a nuclear explosion, unavoidable exchange reactions occur which causes the natural gas itself to become radioactive — far too radioactive for use. This radioactivity is chemically an integral part of the gas, not simply carried along with it. Accordingly, the gas must be disposed of. The most convenient way to get rid of it is flaring.”
The article continues: “The Public Health Service, which made some limited measurements of the flaring operation, found that the radioactivity in vegetation downwind from Gasbuggy was increased by 10 times.”
Aside from the radiated gas, the cost-benefit analysis also proved unworkable.
In a 2011 report, the DOE estimated that even if the gas from the three nuclear fracking experiments was not radioactive, after 25 years of gas production of all the natural gas deemed recoverable, only 15% to 40% of the investment could be recovered. There was the tritium contamination problem, the report noted, and “it could not be proved that national energy needs justified the elaborate procedures that would be required.”
With yet again failed efforts to tweak the bombs and produce more and “cleaner” gas than Gasbuggy or Rulison, Project Rio Blanco marked Project Plowshare’s last nuclear test, and the program was officially abandoned in 1977.
“Burning through $700 million in the process,” wrote Shea, “in the end Plowshare did not achieve a single one of its aims. As the AEC stated in its final report on the program, ‘Plowshare was a program that started with great expectations and high hopes,’ but faced an insurmountable problem: ‘the whole concept tends to appall people.’”
The Hayward family
Project Rulision was unique among the Plowshare experiments in that it took place on private property — a tract of 360 acres owned at the time by 69-year-old potato farmer Claude Hayward.
Hayward’s granddaughter Cristy Koenke today tells the story of the whiskey-fueled last ditch effort by government officials to obtain her grandfather’s signature on what she describes as a one-paragraph contract written on onion paper.
Koenke said her father, Lee Hayward, begged his father, Claude, not to sign the document pushed by the government and oil company representatives promising Claude Hayward $100 a month out of their gas-well profits.
“My dad told him, ‘Don’t sign anything. Don’t trust them,’” Koenke said.
Claude Hayward initially refused, Koenke said. But they returned one evening with more whiskey, proclaiming to “toast to friendship” — until enough toasts led to Hayward’s signature.
“He wasn’t a stupid man,” Koenke said. He had only an eighth-grade education but had amassed a large plot of land and was supporting his family. “He would have never signed something like that unless he was under the influence,” Koenke said.
The dealmakers also appealed to Hayward’s patriotism, Koenke described, saying things such as “You owe this to your country,” and alluding to other national-security-related information that could be gained from the test.
But Hayward never got paid, Koenke said, and the family was never compensated for the irreparable damage to their land or for the loss of what Koenke describes as a small fortune in mineral-rights leasing that could have changed the trajectory of the lives of herself, her brother and their children when natural-gas drilling boomed in the area in the early 2000s.
Koenke, a retired teacher who lives in the Denver metro area, said her family has largely stayed quiet on this painful part of their history — one that she believes cost her grandfather his life.
Claude Hayward died a few years after the Rulison blast as the result of an aggressive cancer. Koenke remembers a large black spot appearing in the center of his chest.
Hayward’s death certificate lists sarcoma as the official cause, Koenke said.
Prior to the Rulison blast, Koenke said her grandfather was as “healthy as a horse” and proud of his physique. The family had no history of cancer, she said.
But Hayward spent time in a cabin close to the location of where the radiated Rulison gas was flared from 1970 to 1971.
Koenke remembers watching the bright flame of the flared gas from the bathroom window of their family home located farther away than the summer cabin.
It was not until many years after her grandfather’s death that she made the connection to the flaring.
Koenke said a lightbulb turned on in her head when she heard news reports about sarcoma being linked to the deaths of people impacted by the Hiroshima and Nagasaki nuclear bombs.
But it was a connection she knew that she’d never be able to prove.
There was also the loss of the natural resource and source of income Claude Hayward sought to secure for his family’s future.
“Our family was sitting on a huge natural gas basin,” she said, “But we were never allowed to drill what would have been as many as 36 natural gas wells on our property. They drilled all around us. We were never paid, and we were never paid for the millions of cubic feet of gas they flared off our property.”
Koenke said that every time her family tried to fight for compensation, she found their pockets were nowhere near deep enough to go up against the federal government.
The family holds other mineral rights in the valley, first obtained by Koenke’s great-grandfather who was the settlement’s first doctor, arriving fresh off the silver and gold rush in Leadville.
But the Rulison mineral rights, had they been realized, would have brought life-changing wealth, she said.
Koenke remains distrustful and resentful of the federal government.
“We, as a family, have been very frustrated with the fact that people have not been upfront with us, have not been honest with us and have stonewalled us,” she said. “It’s very tough for individuals to fight the federal government — it’s almost impossible. And they know it.”
Other Project Plowshare mishaps
Unlike some of the other experimental underground blasts, the Colorado fracking experiment — at least to date and based on what is known about environmental and human health impacts — avoided widespread catastrophe.
A 1958 international ban on nuclear testing paused Project Plowshare, but after Russia broke the ban in 1961, the United States had a number of projects ready to go, the first being Project Gnome on Dec. 10, 1961.
Located near Carlsbad, New Mexico, Project Gnome was designed to capture heat created by the blast before potentially turning it into electricity.
Using a 3.1-kiloton nuke detonated at 1,184 feet underground, the test also provided a novel opportunity for a wide range of data collection. But scientists underestimated the force of the explosion and the blast broke through the tunnel designed to contain it.
Project Gnome allowed radiation to escape above the earth’s surface in the form of a white vapor cloud, although the officials said at the time that radiation levels were still in the “acceptable” range.
It should be noted that the accepted “background” concentrations for radionuclides were higher in the 1960s and 1970s than they are today because of the above-ground nuclear testing conducted in the 1950s.
The Gnome gaffe paled in comparison to Project Sedan in 1962.
To test land-excavation capabilities of nukes at the Nevada Test Site (now called the Nevada National Security Site), a 104-kiloton nuclear device was detonated 635 feet underground on July 6, 1962.
The blast produced a 1,280-foot-wide, 320-foot-deep crater and two clouds of radiation and dust, one reaching 10,000 feet into the air and the other reaching 16,000 feet.
Radioactive debris from the Sedan test first moved north toward Ely, Nevada, before being carried east by wind for thousands of miles, with high levels or radiation measured in Iowa, Nebraska, South Dakota and Illinois.
Project Sedan is cited as the nuclear test that exposed more U.S. residents to radioactive fallout — namely iodine-131 — than any other test.
The explosion did displace 12 million tons of earth, leaving behind the largest manmade crater in the country.
Located northwest of Las Vegas and west of St. George, Utah, the Nevada National Security Site today is pockmarked with craters as a result of 928 nuclear surface and underground tests over 41 years.
Above-ground testing was banned in the United States in 1963, with the widespread impacts from initial tests of atomic weapons for military applications made clear from the get-go. The Trinity test conducted by the scientists and engineers building the first atomic bomb in New Mexico on July 16, 1945, poisoned teenagers attending a summer camp within 40 miles and spread fallout that was detected as far away as New York state.
The 2023 documentary “Downwind” explores the health effects of the Nevada Test Site on St. George and other communities, including increased rates of leukemia, thyroid and 18 other types of cancer; birth defects; miscarriage and infant mortality; and other illnesses.
A study published in 1990 in JAMA found nearly eight times more leukemia in children under 19 who lived in southwestern Utah during the above-ground testing.
After the Sedan test, public health officials in Utah “were particularly alarmed when radioiodine-131 began appearing in milk samples,” Shea wrote. “Indeed, since 1952, much of Utah had been showered with radioactivity from the Nevada test site.”
A 2005 study by the Centers for Disease Control and Prevention and the National Cancer Institute found that any person living in the contiguous United States since 1951 has been exposed to radioactive fallout from testing.
In 1990, the U.S. Government Accountability Office’s Radiation Exposure Compensation Act was signed into law.
“Fears over fallout led many to believe that Plowshare’s goals were, at best, unwise,” wrote Shea. “The fact that many of Plowshare’s tests resembled weapons tests in almost every way also made the distinction between peaceful and military nuclear explosions much less apparent.”
In 1970, astrophysicist Carl Sagan said, “The use of nuclear explosives in programs like Project Plowshare, regardless of the intended peaceful applications, risks irreparable environmental damage and global contamination from radioactive fallout. The Earth’s ecosystems are too fragile to withstand such a gamble.”
What nuclear testing in Colorado left behind
Cowan and Haas remain skeptical that there was never any environmental contamination as a result of the Rulison blast.
Cowan still worries about the blast’s proximity to the Colorado River and expresses disbelief at the 107 days that radioactive gas was burned in order to test whether the radionuclides would eventually become diluted enough to market the gas.
According to the 1973 Rulison Manager’s Report, ”Most of the gaseous tritium was removed from the cavity by the end of the testing. … An accounting of all of the tritium created could not be made because of the large quantity of tritiated water still being recovered at the conclusion of testing and an unknown volume of water remaining in the cavity. A significant portion of the tritium remains bound in the solidified melt zone.”
A 2005 sampling by the Colorado Oil and Gas Commission of five wells near the Rulison site determined that with a halflife of 4,500 days, “approximately 86.5% of the tritium created by the Rulison test and not removed by gas production has decayed in place.” All five wells showed tritium concentrations less than 10 tritium units, “which is considered to be the lower limit of detection.”
Asked about aquifer contamination, Jost, the DOE spokesperson, wrote that because of the depth of the detonation and low permeability of the Williams Fork Formation, “it was concluded that the most likely containment transport path from the detonation zone to the surface would be through a natural gas production well drilled near enough to each site to allow the hydraulic fractures from the gas well to interact with the fractures from the nuclear detonation. … Currently no natural gas wells have been drilled near enough to each of the sites to interact with the fractures from the detonations.”
Today, the closest well at Rulison is a methane-producing vertical well located just outside the 0.5-mile zone around the historic blast site.
Neither Cowan nor Haas believes there was sufficient testing on air quality during the flaring operations.
Anecdotally, Haas recalls an unusual uptick in young people in the Roaring Fork Valley with cancer diagnosis in the 1970s and early 1980s — an increase that made her think about the Rulison flaring.
“All our weather comes from the west,” Haas said.
Koenke recalls that an unusual number of people in the vicinity of the Hayward property were diagnosed with brain cancer during the decade after the blast.
The Colorado Central Cancer Registry’s cancer-incidence data for the region dates back to only 1988, making these anecdotal observations hard to confirm.
According to the DOE Rulsion fact sheet, the Rulison well produced 455 million cubic feet of natural gas in 107 days of testing over four periods from October 1970 through April 1971.
“The produced gas was flared to the atmosphere and samples of the produced gas and water were analyzed to find out how radioactivity levels changed as testing progressed,” the fact sheet reported. “Both the Environmental Protection Agency and the Colorado Department of Public Health and Environmental monitored all releases during drilling and testing to protect workers at the site, the public and the environment.”
According to a 2013 monitoring report for a natural gas well located within three miles of the Rulison test site, prepared for the Colorado Oil and Gas Conservation Commission, in 1970-71, “some of the [tritium] and the majority of the [krypton-85] and [carbon-14] were removed during the gas calibration flaring and production flow testing, leaving [tritium] as the most mobile radionuclide that remains in a sufficient quantity to pose a potential health concern if released.”
According to the manager’s report, the monitoring of the gas during the flaring stage was done by the “one-of-a-kind, experimental” STALLKAT instrument developed for Gasbuggy. “Though certain drawbacks with STALLKAT were readily seen, not the least of which was a poor sensitivity to tritium, it was clearly the best available system.”
During the flaring operation, the gas was separated into gas and water, both products of which were eventually burned and “dispersed into the atmosphere,” according to the report. “Operations would have ceased, pending further data collection and evaluation, if these levels had been exceeded. The levels were arbitrarily set at 10 times the predicted concentrations for tritium and krypton-85.”
In addition to inadequate tritium-measuring equipment for the gas, the report details a number of unexpected occurrences and issues arising, illustrating the project’s highly experimental nature.
“Field changes” were made to onsite operations based on “the difficulty during planning sessions of making aware to inexperienced people the dangers involved in working with radioactive materials.”
The report’s final recommendations pointed to “doubt and confusion as to responsibility and authority” related to the employing of nongovernmental subcontractors.
During the initial attempt at calibration flaring, “the first two flows the STALLKAT was not in operation due to an error in valve settings.”
As “remedial operations began on Sept. 12, 1970, … several spills of contaminated fuel did occur. … Decontamination was also a more demanding chore as tritium levels in contaminating fluids were now much elevated. … Tritium contamination trapped in grease was the major concern.”
On Oct. 4, 1970, “of the numerous samples collected, only four atmospheric moisture (tritium) samples were significantly above background.”
On Oct. 5, air samples collected by the Colorado Department of Health “were within the range of background.”
On Oct. 7, 1970, during an 11-inch snowfall, “Some quite active tritium fell near the blast of the stack early in flaring and some tritium activity was ‘snowed out’ of the flare.”
During December 1970 sampling, the highest concentrations of tritium and krypton were detected about 2.5 miles from the flare stack, according to the report. “Concentrations in populated offsite areas were considerably lower.”
A news release dated May 17, 1971, said that “a small leak had been found on the Rulison control head. Some 50,000 cubic feet of gas was flared while the leak was repaired.”
The manager’s report states the U.S. Geological Survey “conducted a fairly extensive stream and river monitoring program throughout western Colorado. No radioactivity was observed which could be attributed to Rulison.”
The manager’s report provides some reassuring conclusions: “Though there were measurable releases of radioactivity and minor contamination problems, they were within safety guidelines and/or controlled effectively by the contractors responsible, such that no measurable exposure occurred to either onsite workers or offsite populations.”
It concludes: “The radioactive contaminated water handling and disposal was improperly designed and inadequately controlled to meet the varying conditions during production testing.”
Under “recommendations,” the report states that the STALLKAT “should not be used for monitoring tritium” and that “an analysis should be made of radiation criteria required for health and safety of onsite workers vis-a-vis the radiation which is permissible for release to the environment.”
There’s also a vagueness in the wording in some of the conclusions, such as “With the exception of occasional downwind air samples and soil samples from known spill areas, the onsite environmental monitoring showed mainly background levels of radioactivity during and after calibration flaring.”
Another of the report’s conclusions states: “No air samples taken in work areas showed background activity except for tritium water vapor during flaring periods. … Analysis of onsite vegetation and soil samples showed only worldwide fallout and natural activity, except for areas with known spills and the close-in area contaminated with fallout of snowout from the flare stack.”
Koenke said her family has been dealing with 57 years of what she describes as intentionally vague and confusing information provided about Project Rulison’s impacts to their land, air and water.
In the late 1990s, Koenke described a “superfund” cleanup of the area around the blast. She watched firsthand as towering cranes and other heavy equipment worked with a ground crew in hazmat suits to remove massive amounts of dirt and a large pond before replacing it with a much smaller pond.
According to the DOE Rulison fact sheet, which does not designate it as a Superfund cleanup, “Sediment and soil samples from the former pond and areas near the reentry well collected in 1994 and 1995 contained organic drilling additives in the form of petroleum hydrocarbons.”
Thus, the fact sheet continues, the pond was drained, contaminated sediments removed, and eight wells were installed to monitor groundwater. “Water samples collected for eight consecutive quarters in 1996 and 1997 confirmed no migration of petroleum hydrocarbons above risk-based levels.” The monitoring wells were decommissioned and the site was officially closed in 1998 with a determination of no further action needed, according to the fact sheet.
The family has since sold two parcels of land, including the site of the original Rulison well and reentry well, but the Hayward family still owns 292 acres covering the land above the blast, Koenke said. The DOE persuaded Koenke’s father to give the government control of the Rulison mineral rights, but the rights, Koenke said, are still owned by the family, who have refused to relinquish them.
Shea writes of the larger Plowshare program: “Consequences of the project included blighted land, contaminated water, and the dispersal of radioactive fallout that will never be calculated. Plowshare scientists’ tendency to downplay or outright ignore those hazards established a deep sense of distrust among the public. At their worst, Plowshare’s projects were arrogant and reckless. These factors ultimately led to the project’s demise and, unexpectedly, helped spur the emerging environmental movement.”
The birth of a movement
The Rulison and Rio Blanco tests did not go off without a significant fight from Coloradans.
Legal pushback and safety concerns pushed the Rulison test from May to September, and weather pushed it from Sept. 4 back to Sept. 10.
Just before the bomb went off, Denver lawyer Tom Lamm — working with brother Richard Lamm, who was then a state representative but would go on to be Colorado’s governor from 1975 to 1987 — flew to Washington, D.C., for a hearing before U.S. Supreme Court Justice Thurgood Marshall in an effort to stop the blast with an emergency injunction.
It was one of three injunctions filed in an effort to prevent the detonation.
The Rulison countdown began as soon as the Lamms lost in court, but the environmental activism sparked by the effort is credited for helping to launch Richard Lamm’s bid for governor and subsequent efforts to reject the hosting of the 1976 Winter Olympics.
U.S. Rep. Teno Roncalio, D-Wyo., opposed similar proposed nuclear tests in his state for different reasons, arguing that Plowshare tests were “literally throwing away a vital resource, a resource that once it is gone, can never be replaced.”
On Sept. 2, Haas and Cowan joined a large gathering of concerned citizens at a meeting with representatives from the AEC and their oil and gas partners held at a lecture hall at the Aspen Institute.
Cowan recalls a large turnout “packed with scientists” with well-informed concerns and questions about the test. He remembers that one professor claimed, “This is nothing but a nuclear weapons test.”
The end result of radiated gas, to many, seemed obvious before the test took place, Cowan said.
To Cowan, protesting against the Rulison test at the early stages of Colorado’s environmental movement seemed a cause with wide appeal — and one less political than the anti-war demonstrations happening at the same time.
Walking to school in Aspen from his home in Snowmass Village to mark the first Earth Day in 1970, Cowan said he remembers the idea of protecting the natural environment “felt like something we could embrace — and have it be less controversial. The environmental imperative was so obvious.”
Cowan, an anti-Vietnam War activist during high school, paid a price for his politics in the small community, from being called a communist on the street to being “blackballed” by teachers and coaches and ultimately losing college scholarships.
Cowan recalls the courageous teachers who helped awaken his political awareness during those high school years, which he describes as formative. He maintained a lifelong friendship with Benton, and he later wrote about detrimental impacts of nonnuclear fracking for Aspen Sojourner magazine, where he served as editor.
After protests and legal action failed to stop the Rulison test, civil lawsuits were filed by several groups after the fact in an attempt to stop the flaring.
A judge concluded the flaring did not pose a substantial threat and sided with the gas company, saying the plaintiffs had “failed to show the probability of irreparable damage if the flaring is not enjoined.”
As a result of the lawsuit, however, the plaintiffs won standing to sue in the first place.
“The importance of this ‘win’ could not be understated,” Thompson wrote in his Historical Studies Journal article. “The AEC has previously enjoyed a kind of immunity in its atomic testing due to a previous appeals court’s ruling that citizens did not have standing to sue the government on the matter of nuclear testing and that the appeals court lacked jurisdiction to hear the matter in the first place. … A new avenue of recourse was opened.”
Protests and a class-action lawsuit filed by a coalition of environmental groups then tried to stop the Rio Blanco test.
Those efforts also failed, but public opposition was growing bigger and louder and Rio Blanco marked the end of the Project Plowshare program.
Opposition then coalesced around the citizen-initiated Colorado Detonation of Nuclear Devices Amendment, or Measure 10.
Exceeding the required 50,000 signatures, Colorado organizers obtained nearly 70,000 signatures, and the measure appeared on the November 1974 ballot, successfully asking voters to pass a new law prohibiting “the detonation of nuclear devices in Colorado except when approved by voters at a general election and [requiring] that the governor assign a state agency to ensure financial resources to repay those who incur damages as a result of the nuclear detonation,” according to the ballot language.
“The language and intent were clear,” wrote Thompson. “The right to conduct nuclear tests had to be conferred by the people who would have to live with the consequences.”
Rulison and Rio Blanco today
Gunnison attorney Luke Danielson did not get involved with Rulison until around 2007, when a natural-gas boom enticed oil and gas operators to seek permits to drill closer to the detonation site.
Carbondale-based Public Counsel of the Rockies — a nonprofit legal organization founded by Tim McFlynn, a late board member of Aspen Journalism — reached out to Danielson to request representation for several families who lived near the Rulison site and wanted to stop new efforts to drill.
Danielson and his clients did not win the case and prevent additional drilling within one-, two-, and three-mile zones around the site, but a larger win came about with a rewriting of Colorado procedural rules, effectively awarding citizens who were concerned about oil and gas drilling near their homes an opportunity for a hearing before the Colorado Oil and Gas Commission. The commission also became more balanced and less cozy with industry than earlier iterations, Danielson described, as “the rules were largely written by the oil industry back in the day.”
A 2005 High Country News article reported that “In February 2004, Presco Inc., a Texas-based energy company, announced its plans to drill for natural gas in the area surrounding the blast site, and began applying for state permits.” Some permits had already been granted, and “if all goes as planned, the company will drill at least 65 wells in the area, some as close as a half-mile from ground zero.”
Over his career, Danielson has represented members of the Navajo tribe in New Mexico and Marshall Islanders impacted by radioactive fallout, as well as a family in South Dakota living near a uranium mill.
When it comes to trusting the U.S. government to protect human health, Danielson points to one of history’s most egregious examples: Project Desert Rock. From 1951 to 1957, a series of above-ground nuclear tests were conducted in Nevada during which soldiers were directed to march toward the detonations in order to train troops and study military maneuvers and operations on a nuclear battlefield. Known as “atomic veterans,” soldiers developed health problems later in life and some (or their family members) were compensated under the 1990 Radiation Exposure Compensation Act.
Danielson is currently working to oppose bringing nuclear power back to Colorado, having seen firsthand what its waste can do to the environment and the people who live near it.
“The people who are promoting it are not telling the whole story,” Danielson said. “We still haven’t cleaned up the mess from the last round of uranium mining. We still haven’t figured out what to do with the nuclear waste from the last round. Why would we generate more if we don’t know where to put what we’ve already got?”
He pointed to numerous uranium mill tailings left behind at sites around Grand Junction and western Colorado, and the high cost of cleanup. Uranium mining in the state peaked in the 1950s, continuing until the market crash around 1980.
In the 1969 Time magazine article, biochemist H. Peter Metzger said of the AEC: “The last time they supervised anything in Colorado, they allowed uranium miners to leave radioactive tailings lying around that could be blown over homes, farms, and grazing lands, and carried hundreds of miles downstream by rivers.”
On Rulison, Danielson agrees with the DOE that more-recent drilling efforts most likely did not “get close enough to intercept Rulison gas.” However, he isn’t confident that it couldn’t happen in the future.
“We don’t know how close you’d have to drill to have radiation come out, but we were on a road to find out,” he said.
In 2007, the biggest fuel-frenzied push to drill closer to the Rulison detonation site in recent history, Danielson commissioned an independent analysis by Dr. Robert Moran of Golden-based Michael Moran Associates, a consulting firm with expertise in water quality, hydrogeology and geochemistry.
Moran expressed concern about the many remaining uncertainties, despite existing regulations and monitoring going on at the time.
In his report, Moran wrote that “these created pathways, generated by both the original Rulison test blast and the hydraulic fracturing techniques provide the enhanced pathways for possible migration of radionuclides and other contaminants in the Rulison region. In addition, the existence of hundreds of water and gas wells, many of which have never been adequately completed or abandoned, provides extensive potential pathways for migration of subsurface contaminants in the form of liquids and gases.”
According to the DOE’s Jost, “At the Rulison site, it was determined through the production testing in 1970 and 1971 that the fractures from the detonation extended less than 300 feet from the detonation.”
In his 2007 analysis, Moran concluded: “The present regulatory process that allows drilling near the Rulison test site is filled with uncertainties and unanswered questions. The magnitude of what could go wrong is considerable; future problems could be practically irreversible, with damage that is very hard and/or expensive to remediate.”
Regarding the reports compiled by government agencies up until 2007, Moran wrote, “With a few exceptions, the institutional and intellectual bias of these reports is impressive. Despite the weight of these supposedly disinterested reports, there are numerous sound technical, financial and political reasons why reasonable citizens should be concerned about the proposed drilling within the immediate area of the Rulison Project.”
After the 2007 lawsuit, Danielson said boom largely turned to bust and not all of the companies seeking permits ended up drilling or building the oil and gas infrastructure.
Today, the Colorado Energy and Carbon Management Commission (ECMC) has authority over permit applications and requires a special hearing for oil and gas development plans within a 0.5-mile radius of either site, where there are currently no natural gas wells. There have not been any special hearings for operators seeking to develop oil and gas infrastructure in that closest zone which encompasses about 500 acres, according to Kristin Kemp, public information officer and community relations manager for the ECMC.
Drilling below 6,000 feet is prohibited on a 40-acre boundary surrounding the site. The Colorado Department of Public Health and Environment acts as the DOE’s consultant on environmental matters, according to Jost.
There now is a massive amount of publicly available data on the ECMC website regarding permitted wells and testing results around the Rulison and Rio Blanco sites.
Within two miles of the sites, oil and gas operators must adhere to sampling regulations.
Within one mile of the sites, DOE “provides independent confirmation of the results” with its own well sampling.
There are eight wells currently being monitored by the DOE within the one-mile radius of Rulison, with no producing wells located within one mile of Rio Blanco, Jost wrote.
“The monitoring program for the Rulison site includes collecting samples from a surface water location, shallow groundwater wells, and natural gas-producing wells near the site to monitor for potential contamination that might be attributed to the Rulison nuclear test,” according to a February 2025 DOE report.
There are at least 40 permitted drilling sites within the three-mile radius of Rulison, many with multiple wells. However, many wells are listed as “abandoned location” and appear to have never been drilled.
“Wells have not been drilled near enough to either of the detonation sites to bring contaminants to the surface,” Jost confirmed of Rulison and Rio Blanco in the Dec. 20 email.
In a 2016 independent review of a 2015 well sample located within the one-mile radius of the Rulison site, the report concludes that a retest three months after the first two tests found tritium above “method detection limit, but below the RSAP [Rulison Sampling and Analysis Plan] screening level … was most likely a false positive.” However, the report added: “Careful attention should be given to future sample results from this well.”
Jost noted that the wells currently being monitored at Rulison are “in the later years of their production cycle, meaning they are producing less gas, so they are sampled less frequently (currently every three years).”
The ECMC’s most recent Rulison well-monitoring report is from 2015, but Kemp noted that the DOE has continued to monitor water and gas over the past decade and posts reports on their website.
Both Cowan and Danielson note there are also plenty of nonnuclear environmental concerns across the heavily drilled region of Garfield and Rio Blanco counties related to natural-gas flaring and numerous abandoned wells, often with lackluster enforcement on cleanup regulations.
Danielson sees every reason to remain cautious about potential future impacts of Colorado’s unique place in the history of nuclear testing, especially through the booms and busts of oil and gas exploration and changes to political leadership and industry regulations.
“There’s always the chance the government is going to go off the rails and make decisions that are very dangerous to the public,” Danielson said. “Eternal vigilance is the price of liberty. People have to be aware of what is going on and ready to speak up for their interests.”