The Atom Comes to Colorado: The 1969 Project Rulison Peaceful Nuclear Explosion Test and its Consequences for Colorado

By Zachary Thompson

At 3:00 p.m. on Wednesday, September 10, 1969, the Atomic Energy Commission and two of its private sector partners buried and detonated a nuclear device 8,425 feet underground near Rulison, Colorado. At forty kilotons, the nuclear device contained a yield that was about two to two and a half times that of the Fat Man and Little Boy atomic weapons that leveled Nagasaki and Hiroshima. As part of “Project Plowshare,” the United States’ on-going testing program for “peaceful uses of nuclear explosives,” scientists designed the Rulison test to see if they could recover usable quantities of natural gas from areas normally considered to be economically unfeasible using conventional extraction methods. The citizens of Rulison and other nearby communities were distressed, and they worried about the threat that a nuclear detonation could pose. To combat the danger, several Coloradans and a non-profit organization initiated civil action lawsuits to prevent Project Rulison from harming the citizens and the environment of the region. Such action from the people of Rulison and from throughout Colorado eventually culminated in the adoption of one of the most unique amendments in the state’s history. The use of nuclear weapons for testing within the state would be regulated, and the power to approve of tests such as “Project Rulison” would be assumed by the people of Colorado, not the federal government or private sector companies.[1]

            The Cold War resulted in the buildup of the largest weapons arsenals in human history. Nuclear weapons were among the most important weapons in these arsenals, and countries like the United States developed, tested, and stockpiled them in eye watering numbers. Indeed, over the course of the late twentieth century the Soviet Union and the United States both accumulated enough nuclear weapons to destroy one another several times over, though neither country used their weapons in combat for fear of nuclear retaliation by the other. [2] Yet, after some time had passed, the itch to use these nuclear arsenals apparently became too tempting to ignore. 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? Of course, the most well-known “peaceful” implementation of nuclear energy are nuclear power plants that produce immense amounts of energy that help drive our industrial societies. But scientists wondered if the nuclear weapons themselves could be repurposed for activities outside of war.

            Born from this line of thinking were peaceful nuclear explosions (PNE’s) which scientists conceptualized as creative solutions to some of mankind’s toughest problems. Proposed uses for PNE’s included excavation of canals and lakes, fossil fuel stimulation, extinguishing out of control gas well fires, creating underground spaces for storage, and even the destruction of asteroids. The Soviet Union alone conducted 124 PNE tests over the course of the late twentieth century, which included an ambitious, yet ultimately futile, attempt to create a 65-kilometer-long canal with a chain of PNE blasts.[3] The United States’ PNE program took the form of “Project Plowshare” which conducted nuclear tests in the sixties and seventies.

            The enthusiasm and optimism that the scientists of Project Plowshare felt was not universally shared throughout the United States. The prospect of nuclear testing in the backyards of Americans upset and concerned both citizens as well as third party groups that were worried about the environmental implications of large scale nuclear testing.[4] Over the course of the late twentieth century, environmental and safety concerns from citizens produced a pattern of pushback against nuclear testing in the United States. The Rulison test certainly fits into this pattern and the legal fight in its wake represented an early fight in the environmental movement.[5]

            The subject of PNE testing represents a small part of the vast topic of the “atomic age” which includes not only the bombs, nuclear testing, and the science behind them, but also the politics, economics, and social values of the era.[6] Scholars have contributed to the study of nuclear testing and PNE’s for decades. Yet, in exploring the topic, they overwhelmingly assess nuclear testing within the context of their consequences for humans, test ban treaties, or other frameworks as opposed to “peaceful” nuclear testing along the lines of Project Rulison.[7] Indeed, this is reflected by the body of literature pertaining to PNE’s which is far from robust, mainly consisting of scientific or policy analyses of PNE tests. While literature exists about Project Plowshare, it is almost always addressed as an afterthought within the context of broader topics like the atomic age.[8] A notable exception to this is Scott Kirsch’s Proving Grounds which is dedicated to exploring the history of Project Plowshare and is centered on its public perception, scientific uncertainty, and opposition to the project. Though it is extensive, Kirsch barely discusses Project Rulison and the environmental movement that formed in its wake. As such, there is little literature pertaining to the nuclear testing done during Project Rulison and its implications for Colorado.[9]

Historical scholarly literature pertaining to environmentalism has addressed a diverse array of topics from nuclear testing to the role of legal action, and Rachel Carson’s 1962 book Silent Spring serves as a foundational environmentalist text.[10] Here too, PNE’s fit under the umbrella topic of nuclear testing. Scholars have explored much pertaining to the intersection between nuclear testing and environmentalism, but PNE tests have not been treated with the same attention as other topics like military applications tests. The Castle Bravo test of 1954 and the Amchitka tests executed between 1965 and 1971, for instance, were concerned with exploring the military role of nuclear weapons and have been given far more attention by scholars than the PNE tests of Project Plowshare.[11] As such, scholars have neglected to assess Project Rulison’s role in environmentalism.

            A further look at Project Rulison reveals that it strained the relationship between the people of Colorado and the federal government. Project Rulison revealed Coloradans’ fear that their government prioritized the execution of the nuclear test over the citizens’ safety and the preservation of the environment. As a result of this conflict, the people of Colorado took legal action to stop the government and its private sector partners from causing undue harm. This paper tells the story of Project Rulison and explores its role in sparking anti-nuclear environmentalism within Colorado. It will first look at the history of fossil fuel extraction in Rulison and Project Plowshare. Then it will tell the story of the nuclear test itself, spanning the period before the detonation and its immediate aftermath. After this foundation is laid, the paper will investigate the reactionary lawsuits where Coloradans fought against the government and its private sector partners. Finally, it will explore the Rio Blanco PNE test in the context of post-Project Rulison Colorado and the Colorado Detonation of Nuclear Devices Amendment which represented the culmination of activism against nuclear testing in the state by its citizens.

Early Speculation and Project Plowshare

            Interest in oil shale extraction in western Colorado began as early as 1913 when the U.S. Bureau of Mines began exploring the quality of shale deposits near Rulison. By 1926, the bureau set up a plant and mine to extract, refine, and test the oil that could be extracted from the Rulison area. The operation was relatively extensive, consisting of, “two retorts, [a] machine shop, store house and boilerhouse [sic] combined, combination office, laboratory and bunk house, control house, and mess house.” [12] Over the course of its nearly four-year operation the mine extracted over 3,500 barrels of oil from the ground. The Bureau, however, shut down the operation on June 30th, 1929, because the oil had a high sulfur content and because the refining process resulted in greater losses than for petroleum refinement.[13] For the time, conventional extraction methods proved too costly to make the Rulison shale a worthwhile venture. This would not be the end of the story for Rulison though, as the advent of the atomic age brought with it renewed hopes of finally extracting the oil that eluded the old-timers in the twenties.

            When scientists developed the atomic bomb and after the nuclear itch became too tempting to ignore, the Atomic Energy Commission (AEC), the forerunner of the U.S. Department of Energy, conceptualized and implemented Project Plowshare. It officially began in 1957, and between 1961 and 1973 the agency conducted twenty-seven PNE tests, which included 35 individual blasts. The Plowshare scientists envisioned the use of nuclear devices in massive civil engineering projects such as in canal, harbor, and highway construction, and especially for natural gas and oil stimulation. There were several notable tests that occurred as part of the operation before Project Rulison. Scientists conducted the first Plowshare PNE test, dubbed the Rainier nuclear test, in Nevada in 1957 with a small device of 1.7-kilotons. It proved successful enough to encourage further testing. The Sedan blast of 1962 at Yucca Flat in Nevada involved the detonation of a 104-kiloton device and resulted in the largest release of radioactive fallout during the program.[14] Finally, the Project Gasbuggy test of 1967 in New Mexico was a fossil fuel stimulation project along the lines of the Rulison detonation. With all the experience from these previous tests, the Plowshare scientists were ready to initiate a new round of testing in Colorado.[15]

Project Rulison

Rulison was, and still remains, an unincorporated community on the western slope of the Rocky Mountains in the state of Colorado. It is located in Garfield County in the northwest quadrant of the state. Today Rulison sits along I-70 and is about 192 miles west of Denver, the capital of Colorado. In its immediate proximity are the town of Rifle, which rests 12 miles to the northeast, and the city of Grand Junction, which rests 40 miles to the southwest. Although there is no census data for Rulison at the time of the nuclear test, Garfield County had a population of 14,821, and Rifle and Grand Junction had populations of 2,150 and 20,170 respectively. In contrast, the city of Denver had a population of 514,678 at the time. Garfield County itself was largely rural with only about 27% of its population residing in urban areas. Overall, the region was relatively quiet until the events of September 1969.[16]

This quiet, unincorporated community is what the Plowshare scientists found when they arrived in the region to prepare for and conduct their PNE test. Austral Oil Company, a Texas based firm, and CER Geonuclear Corporation, a Nevada based firm, were two private sector companies that worked with the AEC during Project Rulison. Both firms initially proposed the test and then helped fund it.[17] Project Rulison, as the test later became known, was described by the AEC as, “a cooperative research effort between the government and Austral [and CER] to culminate in a joint evaluation of data produced from the experiment to assess the commercial feasibility of stimulating a natural gas reservoir using a nuclear explosive.”[18] The activities of the AEC, Austral, and CER stirred up a lot of noise and controversy in the once quiet region.

Figure 1: The Project Rulison Site
An image depicting the Project Rulison test site. It points out both the area where the test was controlled from and “ground zero” where the nuclear device was lowered into the ground and then detonated. It also depicts the environment of the region which was hilly and rural.
“PROJECT RULISON: POST-SHOT PLANS AND EVALUATIONS.” U.S. Atomic Energy Commission. December 1969. United States Department of Energy Office of Science and Technical Information.

Project Rulison was not confidential, so the public knew about it well in advance. Contemporary local and state newspapers frequently wrote about it. One such newspaper, the Rocky Mountain News, drew attention to the pushback that had mounted against the test. On September 4, 1969, an article noted, “in Washington, following normal procedure in the Supreme Court, Justice Marshall gave no reason for his refusal [to block the test] … Meanwhile in Denver, U.S. Dist. Judge Alfred Arraj again refused to halt the blast.”[19] As late as one week before the detonation, Coloradans were making serious efforts at both the federal and state levels to block the nuclear test. Colorado residents’ pushback formed largely out of the fear that the nuclear detonation would cause earthquakes, damage property, and release radiation into the environment, especially into the underground water of the region.[20] This last point about the environment was especially important because, as time went by, environmental concerns became more relevant, and opponents of the testing cited them with increasing frequency to argue for stopping the test. The dissenters were unsuccessful, but their pushback got the proverbial ball rolling and eventually resulted in the legal restructuring of nuclear testing within the state of Colorado.

            Despite what some people may have feared at the time, the AEC did not pursue the nuclear test blindly and it did not neglect preparation in the period preceding the test. The AEC and its partners put much effort into assessing the risks posed by the test and the potential damage that it could cause. For instance, the AEC contracted John A. Blume & Associates Research Division (JAB), a prominent engineering firm, to assist with the “pre-shot” preparations. The firm was specifically charged with, “preliminary reconnaissance, a structural inventory, and detailed condition surveys of selected structures… within the range of potentially damaging ground motion.”[21] The scientists clearly understood the implications of detonating a nuclear device within the proximity of population centers and wanted to get ahead of potential problems. The same pre-shot report reveals that the hazard of injury was significant enough that the AEC intended to evacuate everyone except for project personnel within a roughly seven-kilometer radius of ‘ground zero.’[22]

            The agency went into depth with its pre-shot evaluation efforts, making visitations to other sites and estimating damages. JAB went so far as to visit most of the towns, residences, and landmarks within the area. At all these sites they predicted the potential levels of damage each one might receive alongside the estimated monetary values of those damages. This took a considerable amount of time as some of the locations were dozens of kilometers away. For instance, JAB assessed the city of Grand Junction for the report even though it was sixty-four kilometers away from ground zero. Given the distance, JAB’s engineers predicted that Grand Junction would suffer no damage, and thus add nothing to the tab run up by Project Rulison, but it revealed the lengths they went to in assessing potential effects. The depth of detail in the report indicates the seriousness with which the AEC took the pre-shot preparations.

Many of the entries in the report follow the pattern of Grand Junction and indicate that JAB and the AEC were generally expecting minor damages and thus a relatively inexpensive bill at the end of the day. Yet, several entries highlight the potential for harm that the test posed. The engineers predicted Grand Valley, Colorado, which is ten kilometers northwest of ground zero would suffer “moderate” damage resulting in a bill of $105,000. Likewise, they predicted that Rulison itself would suffer moderate damage totaling $83,000. Had the predictions been accurate, the damages would have been worth upwards of $811,000 and $641,000 respectively, when adjusted for inflation in 2022. As the monetary sums indicate, the test and its potential implications for the region were no small matter. Ultimately, the government elected to proceed with the test despite the potential for destruction that the test posed.

Figure 2: The 40-kiloton nuclear device is lowered into the emplacement well.
            Though it is difficult to tell, this photo captures the moment when scientists lowered the 40-kiloton nuclear device into the well for the test. It was lowered 8,425 feet below ground and placed in a layer of oil shale that it was designed to release. 
             “PNG Plowshare Programs.” U.S. Department of Energy. HD.8A.034. Photo taken 1969. Uploaded December 11, 2013.

            A lot of hope, and profit, rode on the prospects of obtaining the long sought-after fossil fuel of Colorado’s western slope. Poor weather postponed the test for a few days, heightening the anticipation. On September 10, 1969, the weather finally provided a sufficient window for the test. It was an all-day affair, with a briefing session at 6:00 a.m. and preparations continuing until 3:00 p.m. when the device was finally detonated. A progress report written after the test by John K. Emerson, a project officer for the Colorado Department of Health, indicated that the test underwent a “smooth countdown” from the briefing to the detonation.[23]

However, this report ignores a serious incident that occurred on the day of the test. Protesters had planned a sit-in and they intended to sneak into the site with the goal of forcing the AEC to cancel the detonation. As Grace Hood reported in a 2019 article for Colorado Public Radio, a group of protesters did manage to make it near the detonation site. They alerted the government to their presence with smoke flares and government helicopters intercepted them. Yet, the protesters did not make it in time and, being so close to ground zero, they were jolted by the underground explosion. Luckily, no one was injured, but they failed to stop the test. Emerson’s omission of this dramatic series of events is odd, but evidently the AEC must not have believed that the protesters had been any kind of hindrance to the test. After the detonation, the AEC transitioned right into the post-shot testing phase.[24]

In the period following the detonation, the AEC labored to ascertain the effects of the test, paying particular attention to the radiation levels of the region. The testing was extensive and scientists conducted it in three unique ways: air, water, and milk sampling. They sampled air particles during the pre-shot phase as well as after, averaging .56 pCI/m3 before and .39 pCi/m3 afterwards.[25] Water testing likewise took place before and after the test and was very thorough. The scientists took samples from municipal potable water supplies, Battlement Creek, water pollution control sites, and several streams. These results were similar to the air sampling and scientists did not observe an “abnormal increase.” They did note some increased activity in a few samples, but they wrote it off given the “presence of naturally occurring radionuclides.”[26] The scientists completed the sampling of milk from livestock in the same manner which demonstrated that there were no elevated levels of barium, lanthanum, cesium, and potassium in their milk.[27] The AEC, Austral, and CER could not have hoped for better results in terms of Project Rulison’s environmental impact.

            While radiation was the most pressing concern, the AEC and its partners still had to deal with the physical damage caused by the detonation. The government set up an official office in the town of Grand Valley to deal with damage claims on the day following the test. In the aftermath of the detonation, inhabitants of the region made over two hundred and fifty claims at this office seeking reparation payments for a variety of damages.[28] Some claims adhered to what the AEC expected, like Cameo Mine which sought about $8,700 to repair physical damages. Other claims deviated from predicted amounts. For instance, an individual named Gary G. Smith made a claim for $500, claiming that the nuclear test had interrupted a deer hunting vacation.[29]

Business productivity disruption claims also became more frequent. These claimants sought reimbursement for money that they lost in the downtime caused by the test, such as in subterranean mines which could not obtain and process valuable ore. Most of them were for sums of hundreds of dollars, but several also reached four and five figure sums. For instance, United States Steel (Somerset Mine) made a claim for $39,750, citing lost production. This was one of the largest claims that Austral’s lawyers addressed. Though some were comical in nature, the overwhelming majority of claims were sincere petitions about very real damages from Project Rulison. A progress report from after the test highlighted that, as of December 31, 1969, “a total of $56,883,” had been paid with, “the largest damage settlement of $4,795 going to the Union Carbide Corporation Plant at Rifle.”[30] These figures revealed that, while PNE fossil fuel stimulation might eventually prove lucrative for the government and private companies, it was a burden for many others who had the misfortune of living within the proximity of the tests.[31]

The Growing Pushback: Civil Actions Nos. 1702 and 1712

            The story of Project Rulison could have ended with the culmination of the test because the natural gas extracted during testing proved unmarketable given its radioactivity.[32] However, the people of Colorado were not done with the issue. The pushback against PNE testing grew after the test, thus, Project Rulison did not fade into memory. A progress report from after the detonation assessed the growing apprehension of the public:

The ground shock effects on structures have caused more consternation and controversy among the area’s residents than any other factor… Even though the damage has been relatively minor and the compensation settlements prompt and fair, many people have expressed apprehension about any possible future development of the Rulison Gas field using underground nuclear detonations.[33]

Figure 3: “Rulison Post-Detonation Cross-Section”
            An image generated to visualize the effects of the Project Rulison detonation. It displays a cross section of earth and provides much information including the position of different geologic layers, the subterranean location of the detonation, the location of wells, and most importantly helps depict the cavity created by the explosion.
            U.S. Department of Energy Legacy Management. “Fact Sheet: Rulison, Colorado Site.” Last modified April 2020. Accessed March 2, 2022,

The physical damage of the test remained at the forefront of everyone’s attention for some time and was a prominent cause for pushback against the AEC. Shortly after, the concern shifted to the environment as the AEC and its partners prepared to begin “flaring” the created wells. Flaring, a common process in natural gas extraction, occurs when unusable gas is brought to the surface and burned off. This especially worried the residents of the region as the gas was possibly contaminated with radiation from the nuclear explosion. They feared that, if flared, the gas would release hazardous quantities of radiation and contaminate the surrounding environment. The mounting negative sentiment against the Project Rulison flaring quickly manifested in civil action lawsuits against the AEC and its partners.

            Several groups were concerned enough about the flaring to initiate these civil suits. One group of plaintiffs included Charles Morgan Smith, James Hopkins Smith III, Richard L. Crowther, and Willard Eames, all of whom owned or frequented property in the vicinity of the test. Their suit, C-1702, represented the concerns of the people closest to the flaring operation who would have to live with any environmental damages. The defendants in the case were Dr. Glenn Seaborg, the chairman of the AEC, as well as Austral Oil Company, Inc., and CER Geonuclear Corporation, the two private sector firms that had proposed, funded, and helped execute the test. A second plaintiff, the Colorado Open Space Coordinating Council (COSCC), filed another suit, C-1712. COSCC was a non-profit that focused on environmental concerns within Colorado. They filed their suit with the broader goal of protecting the natural resources of Colorado. The court consolidated the two cases under Crowther v. Seaborg as part of the proceedings. The case became an environmentalist fight because the plaintiffs of the case largely argued on behalf of the safety and health of the environment.[34]

The court case explored the same divisions between concerned residents and the agencies of Project Rulison that plagued the project from the beginning. Pre-trial documents indicated that the plaintiffs sought outright to prevent flaring the gas released by Project Rulison. The plaintiffs argued that the flaring posed a severe risk of exposing “the Plaintiffs and all others similarly situated to man-made radiation.”[35] The Defendants, in response, sought to overcome this challenge and maintain their right to flare the gas. This was despite the fact that, by their own admission, the gas “may, and probably will, contain some radioactive nuclides.”[36] The two parties argued over several broad issues, including the impact on the health and safety of the people, environment, and fauna of the region, whether the operation was being conducted safely and under reasonable standards, and whether there were plausible and preferable alternatives to the flaring.[37]

The complicated assertions made by both parties involved technical legal argumentation over two large issues which will be discussed below. It is sufficient to jump to the ruling which sided with the Defendants. Despite the efforts of concerned citizens, Chief Judge Alfred A. Arraj concluded that the proposed well flaring of Project Rulison did not pose a substantial threat to the health and safety of the people, environment, and animal life of Rulison. He argued that the AEC, “planned its activities and is carrying them out with all due regard to the health and safety of the public,” and finished by highlighting that the Plaintiffs had, “failed to show the probability of irreparable damage if the flaring is not enjoined.”[38] It was a discouraging loss for the citizens of Rulison and Garfield County as well as the burgeoning environmental movement.

Yet, while the ruling didn’t go in the plaintiffs’ favor, there was a silver lining. A key aspect of the lawsuit was that the Defendants had fought over the important issues of ‘standing’ and whether the Colorado courts had the jurisdiction to hear and rule on the case.[39] A Rocky Mountain News article from March 18, 1970, assessed that the decision was an “encouraging victory for environmentalists in their long battle to see that some sort of outside civil controls are placed upon the Atomic Energy Commission… The plaintiffs… won the wider issues: Their standing to sue in the first place, and the court’s right to take jurisdiction.”[40] The importance of this “win” could not be understated. The AEC had 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. The Colorado court did not reach the same conclusions. In acknowledging that Coloradans held standing to sue and that the court could make rulings on the PNE tests, a new avenue for recourse was opened.[41] 

            Yet, all the effort that the AEC, Austral, and CER put into their defense proved pointless. The natural gas released and captured during Project Rulison was unsellable. A government report on the Rulison nuclear detonation from April of 2020 confirmed that, “the concentrations of radionuclides dropped throughout the production testing, but the remaining presence of radionuclides within the produced gas made it unmarketable. The government shut the re-entry well after a final test in 1971.”[42] The mere presence of radioactive substances within the natural gas made it a highly unappealing product. Safety concerns were paramount, and consumers hesitated to use nuclear-stimulated gas given the proven detriments of radiation exposure.[43] This rendered any further extraction pointless and interest in the site and project quickly waned. The government and its partners won the battle, but the environmentalists won the war, even if it wasn’t in the way that they had intended to do so.

Beyond Rulison: Rio Blanco and Measure 10

The well that the Project Rulison detonation produced remained shut after the AEC deemed the gas useless, and it was never reopened for further natural gas extraction. Despite the setback of Project Rulison, Project Plowshare continued. Between the temporary plugging in 1971 and the final abandonment of Rulison in 1976, Plowshare scientists conceptualized and carried out a new PNE test in 1973 in Rio Blanco County, Colorado. The new project proved to be the end of PNE testing under Project Plowshare in the United States and for Colorado it provided a second wind of anti-nuclear testing action beyond civil suits.

            The Rio Blanco test was similar to Project Rulison in its goal to stimulate natural gas, but it represented an expansion of the earlier test in one key aspect: it involved the simultaneous subterranean detonation of three nuclear devices.[44] The participants of this test included some familiar names, with the AEC leading the project alongside private sector partners. This included CER Geonuclear, but also a new company: Continental Oil Company (Conoco). The designated site was in Rio Blanco County, Colorado about fifty-two miles northeast of Grand Junction, Colorado. Buried at depths of about 5,800, 6,200, and 6,700 feet, the scientists detonated the three devices on May 17, 1973, roughly three and a half years after the Rulison test. Flaring and extraction followed the test but despite the increased effort, the project ultimately met the same fate as Project Rulison. Fears about the impact of irradiated gas once again made the gas unmarketable, so the government plugged and eventually abandoned the wells.[45]  

Figure 4: Signs marking the spot of ground zero
            Above are a few signs that denote where the nuclear device was lowered and detonated during the Project Rulison test. They warn about the potential for radioactive contamination and advise caution.
            Rocky Mountain News. “MJM666 Signs mark the spot of the Project Rulison Nuclear Explosive Emplacement Well.” July 17, 2007. RMN-052-8409. Denver Public Library Digital Collections. Denver Public Library Archives, Denver, Colorado.

Even though both tests had largely failed, the environmentalists did not cease their fight. Opposition to Project Rulison, and now the Rio Blanco test, coalesced around a new effort to combat nuclear testing in Colorado. This took the form of the Colorado Detonation of Nuclear Devices Amendment, or Measure 10. Where civil action had proven ineffective in the aftermath of the Rulison detonation, a broader citizen-led initiative seemed to be the only way to prevent the government and private sector companies from harming Colorado’s citizens and environment with nuclear testing. The effort was an “initiated constitutional amendment,” meaning petitioning by Colorado citizens led to its inclusion on the ballot, as opposed to through the normal legislative route. At the time, the Colorado constitution stated that for an initiated constitutional amendment to be added to the ballot, it needed a number of signatures “equal to eight percent of the total number of votes cast for all candidates for the office of secretary of state in the previous general election.”[46] The language is tricky, but it essentially established that such an initiative needed relatively substantial support from the citizenry to get on the ballot. The fact that the anti-blast action coalesced around a constitutional amendment signified the continued and mounting pushback from citizens against PNE testing.

The initiative was a citizen-led effort in every sense. Among its most prominent advocates were three representatives from People for Rational Energy Sources (PRES),an anti-blast coalition consisting of environmental and public interest groups which sought to prevent further nuclear testing.[47] These three advocates, Dr. Edward Chaney, Meladee Martin, and Morey Wolfson, all sponsored the initiative and coordinated gathering the 50,000 signatures required to get the amendment onto the 1974 ballot. Their concerns centered on two issues. First, they were concerned about the future implications for Colorado’s environment, particularly if nuclear testing were to continue and expand into thousands of blasts. They were also very concerned about the lack of Coloradans’ say in PNE testing. Dr. Chaney expressed the belief that because Coloradans had to live with the testing, they ought to have a say in how it proceeds. Ultimately, PRES and its three coordinators were wildly successful as they managed to obtain nearly 70,000 signatures on their petition, easily surpassing the 50,000-signature minimum.[48]     

The measure appeared on the November 1974 ballot. The language on the ballot described the measure as, “an act to amend the Constitution of the State of Colorado, to establish procedural steps to be complied with prior to the detonation of nuclear explosive devices, requiring prior approval of the detonation by the voters through the enactment of an initiated or referred measure.”[49] The language and intent were clear. The right to conduct nuclear tests had to be conferred by the people who would have to live with the consequences. The measure passed and the amendment was added to the Colorado state constitution, a sign of the mounting frustration that had built up after years of the AEC getting its way while the concerns of Coloradans went unaddressed. In denying the government the ability to conduct PNE tests at will, it preempted the destruction of the environment and gave Coloradans greater say in events that would transpire in their backyards. The amendment’s success represented a conclusion for the anti-nuclear environmental movement which had been fighting against PNE testing in Colorado since 1969.   

The Sunset of Colorado’s Atomic Age

By 1976, the AEC plugged most of the wells at both sites and cleaned them before abandoning the sites. An Austral report from September 1977 details the process which included the well plugging, decontamination, and disposal of contaminated materials. It notes that by the end of the cleanup the wells were “plugged and abandoned in a manner which was consistent with good oil field engineering practices and approved by both the State of Colorado and the U.S. Geological Survey,” and that it was done in such a way as to, “permanently prevent gas or water migrations from one formation to another.”[50] The Rio Blanco site was wrapped up in much the same way.[51] Aside from future monitoring to make sure no leaks had occurred, the Rulison and Rio Blanco sites had seen their last major activity.

Extensive radioactive contamination never resulted from the Project Rulison and Rio Blanco detonations. Of course, the flaring of the wells resulted in the emission of small amounts of radioactivity, as predicted by the AEC, Austral, and CER in the lead up to the civil action, but it was not disastrous. Their respective fact sheets indicate that the government has periodically tested the sites since their plugging and abandonment in the mid-seventies. These tests have confirmed that the surface and subsurface (i.e. the underground water supplies) of the region have not been contaminated by radioactive material. Whether through the meticulous efforts of the AEC and its partners, the civil action brought forth by Crowther et al. and COSCC, or because Measure 10 was implemented in time, Colorado has avoided the disastrous contamination of its environment from radioactive substances which can follow in the wake of nuclear mismanagement, such as happened at Chernobyl.  

The 1969 Project Rulison peaceful nuclear explosion test inspired intense pushback from the citizens of Rulison and in turn catalyzed the anti-PNE sub-field of the Coloradan environmental movement. Whether they intended to or not, the plaintiffs from the civil action suits and the citizen activists prosecuted an important, and ultimately successful, environmental campaign that had major implications for the future use of PNE’s in the state. Victor John Yannacone, Jr., who was temporarily part of the plaintiff’s legal team during the civil actions, believed it to be a first of its kind series of cases. In assessing the implications of the lawsuit, he argued: “Project Rulison provided the first direct confrontation among the several current theories urged in support of citizen action to protect the environment from federal agency operations.”[52] The idea of peaceful nuclear explosions was perhaps logical, but their nature proved too volatile and the science too uncertain to justify the expansion of Project Plowshare. The seeming lack of empathy by the AEC, Austral, CER, and Conoco did nothing to assuage the fears of Coloradans, so they took measures to protect themselves. Those measures worked.

While PNE fever largely died after the cancellation of Project Plowshare, there are people who continue to wonder if nuclear devices could be used to solve some of our worst problems. For instance, Grace Hood noted in her article that some scientists considered using a PNE to stop the 2010 BP oil well leak in the Gulf of Mexico.[53] Additionally, with energy demands increasing dramatically as the human population continues to grow, there is always the distinct possibility that a Plowshare-like program could return with the goal of exploiting new sources of fossil fuels to meet our energy demands. Much is uncertain, but if momentum builds behind the return of PNE’s, reactive momentum will certainly build for a counter movement. Such activism would build on the foundation that was laid by environmentalists in the wake of Project Rulison.


[1] John K. Emerson, Progress Report V, February 5, 1970, CMSS WH1718, Box 1, Folder: “Rulison Project – Colorado Board of Health,” Denver Public Library Archives, Denver, Colorado. ; “Fact Sheet: Rulison, Colorado Site,” U.S. Department of Energy Legacy Management, last modified April 2020, accessed March 2, 2022,

[2] Robert S. Norris and Hans M. Kristensen, “Global Nuclear Weapons Inventories, 1949-2010,” Bulletin of the Atomic Scientists 66, no. 4, (July 2010): 81. As Norris and Kristensen’s diagram on page 81 points out, at its height in 1967, the U.S. arsenal consisted of over 31,000 weapons. Meanwhile, at its peak in 1986, the Soviet arsenal contained about 45,000 weapons. Truly eye watering figures.

[3] “Peaceful Nuclear Explosions,” World Nuclear Association, last modified December 2018, Incredibly, the Soviets also put out a gas well fire with a peaceful nuclear explosion. The gas well in question, which resided in Southern Uzbekistan, had been burning for nearly three years before a complicated PNE detonation managed to finally put it out. See: World Nuclear Association, “Peaceful Nuclear Explosions” for the complete explanation of several other incredible PNE tests.

[4] D.J. Kinney, “The Otters of Amchitka: Alaskan Nuclear Testing and the Birth of the Environmental Movement,” The Polar Journal 2, no. 2 (December 2012): 291,

[5] Kinney, “The Otters of Amchitka,” p. 292.

[6] Martin V. Melosi, Atomic Age America (New York: Routledge, 2013). Melosi’s book provides a good overview of just how large the topic of the “atomic age” really is. It assesses everything from the weapons that defined the era to the diplomacy of the age, how the weapons generated anxiety, and how atomic energy has been implemented for peaceful purposes. In discussing this last topic, Melosi even briefly looks at Project Plowshare, but only summarizes it over two pages, reinforcing just how small the issue of PNE’s is within the topic of the atomic age.

[7] Ola Dahlman, Svein Mykkeltveit, H. W. Haak, Nuclear Test Ban: Converting Political Visions to Reality (Dordrecht: Springer, 2009).; Sarah A. Fox, Downwind: A People’s History of the Nuclear West (Nebraska: Bison Books, 2014). These are good examples of the ways in which scholars have assessed nuclear testing. The first book looks at the creation of the Comprehensive Nuclear-Test-Ban Treaty and its implications and implementation. The second looks at the impacts of nuclear testing and uranium mining on the environment and people who lived where those activities took place.

[8] Richard Lee Miller, Under the Cloud: The Decades of Nuclear Testing (London: The Free Press, 1986), 311-314. Here the section on Project Plowshare occupies only four pages and thus serves as only a minor historical anecdote within the larger topic of ‘nuclear weapons testing.’ The topic is overwhelmingly viewed in terms of military applications tests such as Castle Bravo and Tsar Bomba as opposed to PNE tests like Project Rulison.

[9] Scott Kirsch, Proving Grounds: Project Plowshare and the Unrealized Dream of Nuclear Earthmoving (New Brunswick, NJ: Rutgers University Press, 2005), 204. Kirsch briefly discusses Projects Rulison and Rio Blanco but only alludes to their impacts within Colorado on page 204. 

[10] Albert K. Butzel, “Chapter 19: Birth of the Environmental Movement in the Hudson River Valley”, in Environmental History of the Hudson River, ed. Robert H. Henshaw (Albany: State University of New York Press, 2011), 497-517.; Rachel Carson, Silent Spring (Boston: Houghton Mifflin, 1962). Butzel’s piece looks at the scenic Hudson court case and its role in launching the modern environmental movement. Carson’s book is very well known and addresses the effects of pesticides on the environment. 

[11] Ellen Griffith Spears, Rethinking the American Environmental Movement Post-1945 (New York: Taylor and Francis, 2020), 112. Spears covers a large range of topics including many relating to nuclear energy, tests, and weapons. She devotes time to the Greenpeace protest of the Amchitka test and even discusses a lawsuit that was brought against the Atomic Energy Commission (p. 112). There is no mention of peaceful nuclear explosions and their role in environmentalism.

[12] Paul L. Russell, History of Western Oil Shale (East Brunswick, NJ: The Center for Professional Advancement, 1980), 27.

[13] Russel, History of Western Oil Shale, 30.

[14] “Yield” refers to the force produced by an explosion. A 1 kiloton nuclear explosion is the equivalent to the explosion of 1,000 tons of TNT. Here this means that the Sedan device had a yield 2.5 times larger than the Rulison device, and about 5 to 6 times larger than Little Boy and Fat Man.

[15] World Nuclear Association, “Peaceful Nuclear Explosions.”; Kirsch, Proving Grounds: Rainier Test p. 38-39, Project Sedan, p. 158-159. By 1975, Project Plowshare was terminated, and though the program was considered a scientific and engineering success, it was an economic failure. This ultimately rendered it undesirable to continue with PNE tests

[16] U.S. Census Bureau, “1970 Census of the Population, Volume 1: Characteristics of the Population, Part 7: Colorado,” January 1973, This paper uses census data from the 1970 census which was conducted closer to the Project Rulison test date than the 1960 census and is thus closer to the actual population of the region in 1969.

[17] U.S. Department of Energy Legacy Management, “Fact Sheet: Rulison, Colorado Site.”

[18] Office of the Chief Counsel Nevada Operations Office, Project Rulison Contract No. AT-(26-1)-429, p. 4, February 1969, CMSS WH1718, Box 2, Folder: “Exhibits A-H,” Denver Public Library Archives, Denver, Colorado. 

[19] “Weather Delays Rulison Blast, Supreme Court Justice Declines to Block Explosion,” Rocky Mountain News, September 4, 1969, pg. 1, Natural Gas: Project Rulison Newspaper Clippings, Denver Public Library Archives, Denver, Colorado. The “Justice Marshall” referenced in the article was none other than Justice Thurgood Marshall.

[20] “Weather Delays Rulison Blast,” p. 1; Tom Rees, “Rulison Blast Put into Plain English,” Rocky Mountain News, September 2, 1969, p. 23, Natural Gas: Project Rulison Newspaper Clippings, Denver Public Library Archives, Denver, Colorado.

[21] John A. Blume & Associates Research Division, Project Rulison: Pre-Shot Investigations and Safety Hazard Evaluations (San Francisco, California: John A. Blume & Associates, 1969), p. 1, E 1.28: JAB-99- 61, Denver Public Library Archives, Denver, Colorado.

[22] John A. Blume & Associates, Project Rulison: Pre-Shot Investigations, p. iv.

[23] John K. Emerson, Progress Report V, February 5, 1970, p. 3, CMSS WH1718, Box 1, Folder: “Rulison Project – Colorado Board of Health,” Denver Public Library Archives, Denver, Colorado.

[24] Thomas Rees, “Rulison Protesters Plan to Hold Sit-In,” Rocky Mountain News, September 2, 1969, p. 5, Natural Gas: Project Rulison Newspaper Clippings, Denver Public Library Archives, Denver, Colorado.; Grace Hood, “Want to Trigger a Nuke in Colorado? Well, Thanks to Project Rulison 50 Years Ago You Need to Ask Voters,” Colorado Public Radio, September 10, 2019.

[25] Emerson, Progress Report V, p. 3.

[26] Ibid, p. 4.

[27] Ibid, p. 5. As comical as it may sound to test milk samples, it proved to be a valid means of measuring for harmful substances in the environment. The report justifies the milk sampling noting, “Milk is a valuable environmental surveillance subject because certain gamma-emitting fallout products, if present on feed and forage, are concentrated in the cow and excreted in the milk.” p. 5.

[28] Ibid, p. 2.

[29] Moran, Reidy, and Voorhees to A. Gordon Stokes, 20 November 1969, CMSS WH1718, Box 3, Folder: “Damage Claims Rulison Detonation,” Denver Public Library Archives, Denver, Colorado. Moran, Reidy, and Voorhees handled much of the post-shot legal matters for Austral. They feature prominently in the civil action that arose in response to Project Rulison.

[30] Emerson, Progress Report V, p. 2.

[31] Moran, Reidy, and Voorhees to A. Gordon Stokes, 20 November 1969.

[32] “Fact Sheet: Rulison, Colorado Site,” U.S. Department of Energy Legacy Management, last modified April 2020, pg. 1, accessed March 2, 2022, This will be discussed further at the end of this section.

[33] Emerson, Progress Report V, p. 2.

[34] “Crowther v. Seaborg, 312 F. Supp. 1205 (D. Colo. 1970),” Justia, accessed April 14, 2022,

[35] Pre-Trial Statement for Civil Actions Nos. C-1702, C-1712, and C-1722, pg. 2, CMSS WH1718, Box 2, Folder: “Pre-Trial”, Denver Public Library Archives, Denver, Colorado.

[36] Pre-Trial Statement Prepared by Defendants for Civil Actions Nos. C-1702, C-1712, and C-1722, 1970, pg. 1, CMSS WH1718, Box 2, Folder: “Pre-Trial”, Denver Public Library Archives, Denver, Colorado.

[37] Justia, “Crowther v. Seaborg, 312 F. Supp. 1205 (D. Colo. 1970).”

[38] Justia, “Crowther v. Seaborg, 312 F. Supp. 1205 (D. Colo. 1970).”

[39] The latter of these arguments is relatively self-explanatory, the AEC argued that the state of Colorado did not hold jurisdiction over Federal matters. The former of the two is more complex and ultimately extremely important. Standing is a demonstration to the court that the aggrieved party is sufficiently linked to a damaging/harmful event or law that they wish to take legal action against. In holding standing, the citizens of Rulison held a legal basis to seek recourse against the AEC.

[40] “A Check on the Commission,” Rocky Mountain News, March 18, 1970, p. 54, Natural Gas: Project Rulison Newspaper Clippings, Denver Public Library, Denver, Colorado.

[41] “A Check on the Commission,” p. 54.

[42] “Fact Sheet: Rulison, Colorado Site,” U.S. Department of Energy Legacy Management, last modified April 2020, pg. 1, accessed March 2, 2022,

[43] Kirsch, Proving Grounds, 204.

[44] It was composed of three separate thirty-three kiloton devices. The combined yield was then over twice the size of the Project Rulison detonation and four to five times the yields of Little Boy and Fat Man. 

[45] “Fact Sheet: Rio Blanco, Colorado Site,” U.S. Department of Energy Land Management, last modified August 2021, pgs. 1-2, accessed April 16, 2022, ; “Peaceful Nuclear Explosions,” World Nuclear Association, last modified December 2018,

[46]  Joanne Ditmer, “Citizens’ Initiative Amazing,” Denver Post, May 12, 1974, p. 27-28,

[47] “Antiblast Petitions Circulating,” Denver Post, March 27, 1974, p. 64. ; Fred Brown, “Colorado to Get 10 Nov. 5 Ballot Issues,” Denver Post, July 7, 1974, p. 3.

[48] Brown, “Colorado to get 10,” p. 3. 

[49] “Colorado Detonation of Nuclear Devices, Measure 10 (1974),” BallotPedia, accessed April 17, 2022,,_Measure_10_(1974). Measure 10 Passed 399,818 to 291,284. That is, 57.85% of voters voted yes and 42.15% voted no.

[50] Energy Research Projects Branch, “Project Rulison Well Plugging and Site Abandonment Final Report,” September 1977, pg. 4, CMSS WH1718, Box 3, Denver Public Library Archives, Denver, Colorado.

[51] “Fact Sheet: Rio Blanco, Colorado Site,” U.S. Department of Energy Land Management, last modified August 2021, pgs. 1-2, accessed April 16, 2022,

[52] Victor John Yannacone, “The Environment and the Law,” The Forum (Section of Insurance, Negligence and Compensation Law, American Bar Association) 9, no.5 (1974): 804,

[53] Hood, “Want to Trigger a Nuke in Colorado?”, Colorado Public Radio.


Primary Sources:

“A Check on the Commission.” Rocky Mountain News, March 18, 1970. Natural Gas: Project Rulison Newspaper Clippings, Denver Public Library Archives, Denver, Colorado.

“Antiblast Petitions Circulating.” Denver Post, March 27, 1974,

Brown, Fred. “Colorado to Get 10 Nov. 5 Ballot Issues.” Denver Post, July 7, 1974,

Ditmer, Joanne. “Citizens’ Initiative Amazing.” Denver Post, May 12, 1974.

Emerson, John K. Progress Report V. February 5, 1970. CMSS WH1718, Box 1, Folder: “Rulison Project – Colorado Board of Health.” Denver Public Library Archives, Denver, Colorado.

Energy Research Projects Branch. “Project Rulison Well Plugging and Site Abandonment Final Report.” September 1977. CMSS WH1718, Box 3. Denver Public Library Archives, Denver, Colorado.  

John A. Blume & Associates Research Division. Project Rulison: Pre-Shot Investigations and Safety Hazard Evaluations. 1969. E 1.28: JAB-99- 61. Denver Public Library Archives, Denver, Colorado. 

Moran, Reidy, and Voorhees to A. Gordon Stokes. November 20, 1969. CMSS WH1718, Box 3, Folder: “Damage Claims Rulison Detonation.” Denver Public Library Archives, Denver, Colorado. 

Office of the Chief Counsel Nevada Operations Office. Project Rulison Contract No. AT-(26-1)-429. February 1969. CMSS WH1718, Box 2, Folder: “Exhibits A-H.” Denver Public Library Archives, Denver, Colorado.

“Pre-Trial Statement for Civil Actions Nos. C-1702, C-1712, and C-1722.” 1970. CMSS WH1718, Box 2, Folder: “Pre-Trial”. Denver Public Library Archives, Denver, Colorado. 

“Pre-Trial Statement Prepared by Defendants for Civil Actions Nos. C-1702, C-1712, and C-1722.” 1970. CMSS WH1718, Box 2, Folder: “Pre-Trial”. Denver Public Library Archives, Denver, Colorado.

Rees, Tom. “Rulison Blast Put into Plain English.” Rocky Mountain News, September 2, 1969. Natural Gas: Project Rulison Newspaper Clippings, Denver Public Library Archives, Denver, Colorado. 

Rees, Thomas. “Rulison Protesters Plan to Hold Sit-In.” Rocky Mountain News, September 2, 1969. Natural Gas: Project Rulison Newspaper Clippings, Denver Public Library Archives, Denver, Colorado. 

U.S. Census Bureau. “1970 Census of the Population, Volume 1: Characteristics of the Population, Part 7: Colorado.” January 1973.

“Weather Delays Rulison Blast, Supreme Court Justice Declines to Block Explosion.” Rocky Mountain News, September 4, 1969. Natural Gas: Project Rulison Newspaper Clippings. Denver Public Library Archives, Denver, Colorado. 

Secondary Sources:

BallotPedia. “Colorado Detonation of Nuclear Devices, Measure 10 (1974).” Accessed April 17, 2022.,_Measure_10_(1974)

Butzel, Albert K. “Chapter 19: Birth of the Environmental Movement in the Hudson River Valley.” In Environmental History of the Hudson River, edited by Robert H. Henshaw, 497-517. Albany: State University of New York Press, 2011.

Carson, Rachel. Silent Spring. Boston: Houghton Mifflin, 1962.

Dahlman, Ola, Mykkeltveit, Svein, Haak, H.W. Nuclear Test Ban: Converting Political Visions to Reality. Dordrecht: Springer, 2009.

Fox, Sarah A. Downwind: A People’s History of the Nuclear West. Nebraska: Bison Books, 2014.

Hood, Grace. “Want to Trigger a Nuke in Colorado? Well, Thanks to Project Rulison 50 Years Ago You Need to Ask Voters.” Colorado Public Radio, September 10, 2019.

Justia. “Crowther v. Seaborg, 312 F. Supp. 1205 (D. Colo. 1970).” Accessed April 14, 2022.

Kinney, D. J. “The Otters of Amchitka: Alaskan Nuclear Testing and the Birth of the Environmental Movement.” The Polar Journal 2, no. 2 (December 2012): 291-311.

Kirsch, Scott. Proving Grounds: Project Plowshare and the Unrealized Dream of Nuclear Earthmoving. New Brunswick, NJ: Rutgers University Press: 2005. 

Melosi, Martin V. Atomic Age America. New York: Routledge, 2013.

Miller, Richard Lee. Under the Cloud: The Decades of Nuclear Testing. London: The Free Press, 1986. 

Norris, Robert S. & Kristensen, Hans M. “Global Nuclear Weapons Inventories, 1945-2010.” Bulletin of the Atomic Scientists 66, no. 4 (2010): 77-83.

Russel, Paul L. History of Western Oil Shale. East Brunswick, NJ: The Center for Professional Advancement, 1980.

Spears, Ellen Griffith. Rethinking the American Environmental Movement Post-1945. New York: Taylor and Francis, 2020). 

U.S Department of Energy Legacy Management. “Fact Sheet: Rio Blanco, Colorado Site.” Last Modified August 2021. Accessed April 16, 2022.

U.S. Department of Energy Legacy Management. “Fact Sheet: Rulison, Colorado Site.” Last modified April 2020. Accessed March 2, 2022,

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Yannacone, Victor John. “The Environment and the Law.” The Forum (American Bar Association. Section of Insurance, Negligence and Compensation Law) 9, no. 5 (Summer 1974): 795-827.

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