Jedediah S. Rogers Historic Reclamation Projects Bureau of Reclamation 2009 Reformatted, reedited, reprinted by Andrew H. Gahan July 2013
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Table of Contents Table of Table of Contents Contents
Project Skywater …………………………………………………………………………………………………..1
The History of Rainmaking ……………………………………………………………………………………2
Postwar Science and Legislation …………………………………………………………………………….8
The Politics of Project Skywater……………………………………………………………………………12
Technology, Testing, and Implementation ……………………………………………………………..19
Government Documents ………………………………………………………………………………………32
Secondary Sources ………………………………………………………………………………………………33
Other Sources ……………………………………………………………………………………………………..33
In 1961 Congress allocated funding for the creation of a weather modification
program headed by the Bureau of Reclamation. Project Skywater came fifteen years after
Irving Langmuir, Vincent Schaefer, and Bernard Vonnegut of the General Electric
Laboratories in Schenectady, New York, successfully demonstrated that “seeding” clouds
with nucleating agents like dry ice (carbon dioxide) and silver iodide produced rain.
Skywater aimed to demonstrably prove that there was a practical basis for weather
modification, as it was popularly called, in terms of cost-benefit and environmental
sensibility. Nevertheless, the task was both daunting and singular. The science behind
rainmaking was embryonic and not thoroughly tested against the complex variables that
govern the weather. Moreover, never before had Reclamation embarked on such a
project: a program of taking water management to the skies, of extensive coordination
with government and non-government entities typically not involved in surface or ground
water issues, of collecting data over a large area, and of understanding a system as large,
unwieldy, and unpredictable as the weather.
In 1964 a report of the National Academy of Sciences produced by a panel of
experts from the scientific community and government agencies gave a grim diagnosis of
the changing of weather. The report critiqued “present efforts which emphasize the a
posteriori evaluation of largely uncontrolled experiments,” and instead proposed “patient
investigation of atmospheric processes coupled with exploration of the technological
applications.” It predicted that even after a very costly and lengthy period of study and
testing, not everything could possibly be known about the atmosphere. The program
required “integrated large-scale studies” on
the structure and dynamics of convective clouds, the physics of precipitation, the initiation of convection in the boundary layer, the effects of cirrus and dust layers on the radiation balance, the dynamics of severe storms, such as thunder- and hailstorms, tornadoes, and hurricanes, and the role of convection therein.1
Reclamation’s Project Skywater was a cog in a larger wheel to address the need
for an integrated program on artificial changes in the atmosphere. Reclamation
concentrated studies and testing in the western states, principally in the upper Colorado
River basin and along the Sierra Nevada in California, for the purposes of managing and
mining water resources, as well as for national defense, public health, and technological
development.2 Never well funded, the program had a decidedly mixed cost-benefit,
environmental, and operational record that never convincingly supported a sound basis
for a national, extensively funded weather modification program.
The History of Rainmaking If the scientific basis behind rainmaking is a modern phenomenon, people, for
ages, have attempted to manipulate the weather. Primitive societies had rainmakers
employing a number of techniques to produce rain, from hanging frogs on trees to
blowing water from special pipes to other forms of homegrownweather magic. In some
American Indian societies native peoples offered human sacrifice in return for rain; in
China people used huge paper dragons to induce rain; in Italy rainmakers stripped statues
of wings or banished the statues of saints until rain appeared. Dr. David Livingstone
1 National Academy of Sciences, National Research Council, Scientific Problems of Weather Modification; A Report of the Panel on Weather and Climate Modification, Publication 1236 (Washington, D.C.: National Academy of Sciences, 1964), 1-4. 2 United States Department of the Interior, Bureau of Reclamation, Project Skywater: An Introduction to Rivers in the Sky, December 1973, 1; the stated purpose of the program was “to explore, develop and determine the feasibility of applying the technology of weather modification to meet the Nation’s increasing demand for clean water.”
reported that, in Africa, natives burned charcoal and other local materials to make rain.
Supplication to gods for rain has been with humans for centuries.
In time religious explanations for rain gave way to scientific or pseudo-scientific
observations. Sometimes the modern notions built on earlier ones. The idea that firing
artillery into the sky would induce rain, for instance, stemmed from the correlation noted
since antiquity that rain followed the battle. Rain came not because the gods found the
carnage offensive or because the blood, sweat, and tears from the slain produced the
condensation for rain. Rather, some believed that the sound of the cannon induced the
rain much as the crack of lightning produced the same result.
A common method of rainmaking was burning, but not until the nineteenth
century did weather modification experiments take on the air of scientific authority.
James Pollard Espy, considered by some to be the father of the U.S. Weather Bureau,
devised a theory of explaining how clouds formed that put him well ahead of his time.
Noting that hot air expanded as it rose, resulting in a drop in temperature and
condensation of air vapor, he predicted that man could generate a cloud if he created hot
air rising in a column. There he gave the scientific basis for the idea that burning/fire
created rain—a phenomenon observed since antiquity. Espy proposed burning large
areas of land—say, 40 acres oftimber every twentymiles in a continuous line north to
south spanning the length of the country—and assured
that the farmers and mariners would always know in advance when the rains would commence, or nearly so, and when theywould terminate; that all epidemic diseases originating from floods and droughts, would cease; that the proceeds of agriculture would be greatly increased, and the health and happiness of the citizens much promoted.”
No such schemes were carried out. After one petition came before the U.S. Senate, John
J. Crittenden of Kentucky urged his colleagues not to give Espy power to cause rain
because “he mayalso possess the power of withholding it, and in his pleasure, instead of
giving us a navigable river, may present us with rocks and shoals and sandbars.” It was
probably a good thing that Congress never funded Espy’s schemes since burning requires
a lot of fuel and energy for yielding, arguably, a scant inch of rain.3
Espy conducted and proposed his methods in the eastern states, where natural
precipitation could support agricultureand water shortage was not acute. West of the
hundredth meridian, however, water manipulation became a matter of survival. The
usual method was to manipulate the water once it reached the ground. The Hohokam
civilization, in central Arizona, is a remarkable yet cautionary tale of the creation of a
complex hydraulic irrigation society in the Southwest that flourished until water scarcity
led,as archeologists believe,to a complete collapse in the fifteenth century.
The first Euro-Americans to traverse the plains region and the far West mostly
perceived the land as wind-swept and arid, largely unfit for settlement. In the plains
region the lack of water and wood made the plains unfit for agriculture and even modest
sized populations. Although the explorer and map maker John C. Frémont suggested that
cattle and farmers could subsist on the native grasses and soil on the plains, overland
immigrants to the West famously passed over the plains with hardly a thought of
lingering. Yet old notions of what the land could support shifted as the East’s
populations moved westward following the call of boosters and agricultural enthusiasts
claiming that “rain followed the plow”—meaning that planting trees and crops altered
3 Clark C. Spence, The Rainmakers: American “Pluviculture” to World War II (Lincoln: University of Nebraska Press, 1980), 9-11, 15.
climate conditions creating more moisture. Congress even encoded in law the notion that
man could alter the western environment by passing the Timber Culture Act in 1873,
which gave ranchers an extra 160 acres of land if theyagreed to plant trees on at least 40
acres of it. Indeed, some believed that empirical evidence proved the theory right, by the
fact that the late 1870s and early 1880s were wet years and hardly typical climatic
behavior on the plains. As climate conditions returned to normal, water was in short
supply, and farmers adapted to that reality by dry farming or using drought-resistant
crops or pumping irrigation water fromshallowunderground aquifers.4
The idea to devise schemes to draw water from the sky stemmed from the age-old
need to locate a reliable water supply. The alluring profit of entering into the rainmaking
business brought people of varying background and knowledge to the task. Their
methods ran the gamut from burning and releasing chemicals into the atmosphere to
concussion and electricity. A common method was to releasedirt, sulphuric acid, or salt
thatlatched onto condensation nuclei in the atmosphere. One idea on the plains was to
build a mammoth artificial ramp a mile high and miles across to lift air as it naturally
rises horizontally across the mountains. The problem was that the rain produced by the
artificial mount would leave other areas high and dry, to say nothing of the material and
money needed to build such a ramp. A number of other schemes ran head-on into
technical and financial improbabilities, such as ideas to use airplanes simultaneously to
blow air from their propellers into the atmosphere, or to warm air on the ground which
would then rise.
4 Howard R. Lamar, ed., The New Encyclopedia of the American West (New Haven, Connecticut: Yale University Press, 1998), 447-8, 1114-5.
Some rainmakers gained special notoriety. During the drought years of the late
nineteenth century Frank Melbourne and Clayton B. Jewell made good money
convincingfarmers that their chemicals induced rain. Another avid proponent of
rainmaking was Robert St. George Dyrenforth of the Department of Agriculture. No one
was more infamous than Charles M. Hatfield, so successful at making rain that according
to one historian “he was accused of washing out dams and credited with saving millions
of dollars worth of crops and defying not only the U.S. Weather Bureau but the elements
as well.”5 Even after supposedly inducing 20 inches of rain in San Diego in 1916 and
escaping liability for resulting loss of life and property, Hatfield continued to collect
upwards of $4,000 for one inch of rain.6
Probably some sincerely believed they could call upon the elements at will even
as they recognized the betting odds. The stories are rife with naivety, gullibility,
deception, faith in progress and science. It might appear perplexing in hindsight why
people would pay well for services of questionable validity, but water users facing
shortage and a failed crop might have seen rainmaking as a legitimate risk to take.
Moreover, although no one could prove the validity of rainmaking, neither could they
disprove it. Who was to say that sulfuric acid or other particulate did not bring down the
rain? How could a farmer desperate for water dismiss as fraud or luck the accurate
predictions of a rainmaker?
A reason these questions could not be answered, people believed, was because no
one had systematically studied the working of weather systems. Centuries of rainmakers
wielding magic, religion, and pseudo-science to modify the elements had relatively little
5 Spence, Rainmakers, 80. 6 D. S. Halacy, Jr., The Weather Changers (New York: Harper & Row, Publishers, 1968), 55-78.
to show for these efforts. Unfamiliar with weather systems and how they worked, most
rainmakers employed a healthy dose of guesswork, quackery, and fraud in their work.
Still, there was not a clear or discernable break between what may be called amateur and
professional rainmakers. Even as scientists gathered more data for understanding and
predicting the weather, the modern science of rainmaking, according to one historian,
owed a great deal to earlier inquiries into weather systems.7
In 1930 three European scientists pushed the experiments and science further than
ever before. August Veraart of Holland triumphantly proclaimed that the dry ice he
dispersed into the clouds caused it to rain, but his voice was so loud and his claims so
extravagant that he was dismissed altogether. At the same time a duo from Scandinavia
and Germany experimented with freezing vapor on ice crystals in clouds and claimed that
“at comparatively slight expense, it will, in time, be possible to bring about rain
None of these men garnered much credit for the first successful cloud seeding.
That honor goes to Irving Langmuir, Vincent Schaefer, and Bernard Vonnegut of the
General Electric Laboratories in Schenectady, New York, in 1946. Langmuir’s work on
cloud seeding is a footnote in a long and storied career as a chemist and inventor. As a
researcher, associate director, and consultant at General Electric,he advanced many
fields and earned top honors for his work, including the Nobel Prize in 1932. Schaefer
was Langmuir’s assistant who gained recognition for having serendipitously discovered
how to form ice crystals in his home ice box—dry ice—which is solid carbon dioxide. In
November 1946 he confirmed, in a four-mile long stratus cloud,—what he tested in his
ice box—that ice crystals formed when clouds were cooled. Not long thereafter, the 7 Halacy, Weather Changers, 79.
younger Vonnegut found that silver iodide could be used to seed clouds to produce rain
Postwar Science and Legislation According to Secretary of the Interior Stewart Udall, in a speech delivered before
the American Meteorological Society, the Bureau of Reclamation took interest in weather
modification in 1947, a year after Schaefer’s seeding demonstrations.9 It was not entirely
surprising that Reclamation would jump into a new field of water management—not after
several decades of broadening water operations to power generation, urban water supply,
and recreation. After initial setbacks, the Great Depression and war era had remade
Reclamation, perhaps most of all by planting a sense of supreme confidence in
engineering and technology and human solutions. If Reclamation could construct the
world’s largest dams and power western cities with electricity, why could it not control
Even still, Reclamation did not immediately take part in the flurry of weather
modification schemes in the wake of General Electric’s cloud seeding tests. Rather,
Langmuir coordinated with the Army Signal Corps, the Air Force, and the Navy to
initiate Project Cirrus. The cloud seeding project reportedly produced numerous
successful rainmaking demonstrations and gathered statistical information that other
government and private entities later used. During the same period, a disparate
community of enterprising meteorologists and privately funded individuals constituted
what one critic called “a flock of quick-buck artists who traveled around the countryside
8 Halacy, Weather Changers, 80, 87-88. 9 “Water Resources in the Sky: an address by Secretary of the Interior Stewart Udall,” Congressional Record, 112 (January 29, 1966): 1489.
convincing water-hungry farmers that they had the secret to the old Indian Rain Dance.”10
Farmers, public utility companies (Bonneville Power Administration paid $59,000 for
rainmakingservices),the sugar industry, aluminum companies, and others spent millions
hiring contractors to seed the skies with carbon dioxide and silver iodide. In 1951 one
seeding company had under contract over 300,000,000 acres in the United States.11
The rush to these rainmaking ventures seemingly reflected the confidence in the
new cloud seeding technology and potential. The men advocating and profiting from the
new era in weather modification tended to be meteorologists—men like Irving P. Krick, a
member of the U.S. Army Weather Board that forecast the weather for the D-Day
invasion, who after the war built a lucrative cloud seeding company and a name in
statistical and long-range weather forecasting.12 In those early years following the war,
weather scientists and lay persons alike spoke of weather control enthusiastically and
assuredly. Vannevar Bush, president of the CarnegieInstitution, told a congressional
subcommittee, “I have become convinced that it is possible under proper circumstances
to make rain…. we are on the threshold of an exceedingly important matter, for man has
begun for the first time to affect the weather in which he lives, and no man can tell where
such a move will finally end.”13
Althoughexperts came to believe that weather modification was possible, it was
still unclear when and how often the proper conditions existed to make rain or whether
rainmaking could be undertaken on a scale large enough to significantly impact the
10 “Drought in Western States and in Florida: Remarks by Senator Peter H. Dominick of Colorado,” Congressional Record, 117 (August 6, 1971): 30626. 11 “Committee to Study and Evaluate Public and Private Experiments in Weather Modification,” Congressional Record, 97 (October 8, 1951): 12738; “Research and Experimentation in Weather Modification,” Congressional Record, 98 (June 21, 1952): 7777. 12 Halacy, Weather Changers, 95-96. 13Congressional Record, 98 (June 21, 1952): 7777.
economy. Also sketchy was the impact of cloud seeding agents in local areas or areas
even as far as 3,000 miles away, as Langmuir believed. To answer these questions
required no less than amassive data-driven program under auspices of a larger apparatus
than private interests could provide. The need for a national, closely coordinated effort to
develop the technology, test the methods, and evaluate the outcomes was acute.
In 1951 ten senators—eight from the Reclamation western states—sponsored a
bill in Congress that called for creation of an independent committee to evaluate the
enormous body of data generated by private and public weather modification experiments
in the country. Initially, the act included a controversial amendment that gave
government agencies authority to indemnify contractors for experiments conducted for
the government. Fearing that the amendment “might expose the Government to
substantial damage suits arising from the experimentation,” lawmakers removed section
10 fromSenate BillS. 2225while considering the bill.14 However, law makers felt it
essential for the government to take the lead in developing the science and technology to
address the efficiency and feasibility of weather control. The government might help to
protect farmers from kooks and scam artists, against fraudulent claims and promises, and
against too much water derived from rainmaking. A significant step in a government role
came in 1953 with creation ofthe Advisory Committee on Weather Control, patterned
after the National Advisory Committee for Aeronautics.15
Like the nation’s vast groundwater stores, which by mid-century had increasingly
become valued as sources of agricultural and domestic water, water resources in the
atmosphere provided a common good. The question was how to regulate and manage a 14 Congressional Record, 98 (June 21, 1952): 7778; “Joint Resolution of Legislature of New Mexico,” Congressional Record, 101 (May 5, 1955) :714. 15 Congressional Record, 97 (October 8, 1951): 12738; Congressional Record, 98 (June 21, 1952): 7777.
resource that belonged collectively to the public. No legal, scientific, or physical means
existed to control or regulate rainmaking. And no political mechanism to regulate
weather manipulation could be createduntil more data existed on how various agents
reacted to different atmospheric conditions, etc. Still, in the minds of some, the
government could not hesitate any longer to intervene in the “uncontrolled and
indiscriminate efforts of many groups and persons to modify climates.” In March 1955
the New Mexico Legislature passed a senate joint memorial urging the Congress to pass a
law prohibiting cloud seeding or other methods of rain induction untilthere was enough
information to regulate it. Reportedly, “a good many people in the Southwest” believed
that rainmaking may be partly to blame for recent drought. Although there was no
evidence to support this hypothesis, tinkering with the weather made some people
The Advisory Committee on Weather Control, created by Congress in 1953,
reported at the end of 1957 that the program of rainmaking required more basic
information and practical experimentation. It recommended sponsoring a research
program through grants and contracts to various federal agencies, universities, industries,
and research institutions. Senator Francis H. Case of South Dakota subsequently
supporteda bill giving the National Science Foundation authority to build a research
program, but it was a start and absorbed only a tinyfraction of the 1959 federal
expenditure of $7.4 billion for scientific research and development. Proponents of
tapping the atmosphere for water commonly compared the miniscule public funding of
rainmaking to the massive NASA program. As Admiral Luis de Florez of the U.S. Navy
Reserve commented in 1961, “I do not imply that we should curtail our space programs 16 Congressional Record, 101 (May 5, 1955): 5714.
in any way, but I do mean that our atmospheric conditions constitute the greatest single
factor controlling the existence of life on earth, and that reshaping the conditions of inner
space to our own advantage should accompany the attempts to masterouter space.”17
The Politics of Project Skywater A long and varied history of rainmaking, then, preceded Project Skywater.
Reclamation did not originate the ideaof rainmaking or usher it into the modern era.
Rather, it gradually assumed a leading role in determining how extensivelyrainmaking
would be used in the future. In 1961 Congress appropriated $100,000 out of the 1962
Public Works Appropriations Bill for research to increase rainfall through cloud seeding.
The project was an experimental program designed to bring together the best minds in
meteorologyand the physical sciences in the public and private sectors. The initial and
subsequent appropriations to Skywater went in large part to universities and private
research organizations contracted out to perform the research. A team of physical
scientists, meteorologists, electronic engineers, technicians, administrative personnel, and
others based in the Engineering Research Center in Denver, Colorado, headed the
program from Reclamation’s end.
Project Skywater complemented the general research program already initiated by
the National Science Foundation as well as the specific weather programs studying
hurricanes at the National Oceanographic and Atmospheric Administration and fog
dispersal at the departments of Defense and Transportation. The difference was
Skywater directedmost of its attentionto augmenting the nation’s water supply. In the
early years the project did laboratory work to use previously acquired information to
17 “Weather—Take It or Make It,” An address by Adm. Luis de Florez of the U.S. Navy Reserve, Congressional Record, 107 (April 3, 1961): 5433-34.
develop cloud seeding techniques. Reclamation later tested this information when it
developed larger field experiments and programs to test the practical application of
seeding technology. Reclamation conducted tests in the West’s mountains to increase
winter snowpack and, later, on the high plains and other areas to develop cloud seeding
techniques in the summer months. In addition, Reclamation performed theoretical and
intellectual work on economic, environmental, and sociological aspects of weather
altering technology. Project Skywater was essentially a whirlpool of ideas, centrally
directed by Reclamation across a broadarea, with cooperation and coordination on the
national, state, and local levels.
What Skywater needed to get up and running was a healthy infusion of cash, but
no such expenditures were forthcoming. Project proponents pointed to the abysmal
funding in the early years. In 1965 Reclamation received a mere $1.1 million for weather
modification, and the next year another $3 million, largely for research in the Colorado
River basin. The enormous expenditures on the space program and even ocean, land, and
other atmospheric studies frustrated proponents of weather modification and Project
Skywater in particular. Senator George McGovern spoke of the congressional funding
for Skywater as “a pittance compared to the billions we are pouring into space
explorationand, more recently, the development of a supersonic transport plane of
Weather modification received a boost in 1966 with Interior Secretary Stewart
Udall’s speech before the annual meeting of the American Meteorological Society in
Denver. Udall cited the crisis of polluted air and water and the desperate need to clean 18 United States Senate, Committee on Appropriations, Public Works Bill, 1962, S.Rpt. 1097, 87th Cong., 1st sess., September 20, 1961, 28; “Rainfall increased over non-mountainous areas by South Dakota scientists,” Remarks by Senator George McGovern, Congressional Record, 114 (January 31, 1968): 1683.
the nation’s skylines, rivers, and lakes. These, he argued, were common goods and
essential resources which needed protection for future generations. Udall spoke in the
tradition ofconservationists who advocate environmental ethic not for protection’s sake
but for nature’s utility to man. To that end he put faith in human solutions and
The secretary reminded his audience that for decades the government had been at
the forefront in damming, diverting, and powering water on the earth’s surface, in taking
water where it pools and channeling it to a field or a power generating plant or a city for
drinking water. “Yet with all our planning and building and looking ahead to try to
outguess the future,” Udall claimed, “we find ourselves still at the mercy of the weather.”
The secretary pressed the point that society had not achieved total control over nature,
particularly the elements. Udall continued,
[W]e must make progress in orders of magnitudegreater than we are now making. Many ways of hastening this progress are open to us and we cannot afford to neglect any of them. But to my mind the most logical and challenging is the one which most stirs the imagination. This is worthwhile utilization of the water resources of the sky.
Then Udall waxed eloquent about “the idea of enormous rivers of water flowing
over us in the atmosphere; of huge pools of moisture poised above our heads; of
enormous reservoirs in vaporous state sailing majestically over mountains, or pumping
into them and dropping their precious burdens too soon.” What might it take to tap into
and manipulate that enormous water supply? No less than total control over the
knowledge of water in the atmosphere by bringing together the best minds, the latest
technologies, and mapping out weather patterns. The secretary urged Congress to
recognize the national importance for this research claiming,“We have no alternative but
to be knowledgeable of the water budget of the atmosphere, day-in and day-out, over any
part of the United States, over the Nation as a whole, over this entire continent and the
oceans which bound it.” Then, in issuing the challenge heevoked the spirit of
Reclamation emphasizing that it was not a question of “‘Can we do it?’ but rather, ‘How
soon can we do it?’”19
Udall was not the lone voice of support in the early years of Project Skywater.
Politicians, Reclamation’s commissioner, and others spoke of the good and necessary
step to fund fully the nation’s weather modification programs. Floyd Dominy, in a
speech given in 1967, spoke of “[t]he wealth of water in both ocean and atmosphere,
evident to all, [that] has, through history, just evaded mankind’s eager grasp.” “We have
been like the legendary Tantalus, who was doomed to stand neck deep in water which
flowed away as he bent his head to drink it, and to reach everlastingly for luscious fruit
hanging just before his mouth, only to have it swung away out of reach by the breeze,” he
said. Dominy emphasized the great strides researchers had made, “Now we are near to
breaking the spell and winning the prizes both from the limitless sea and from brackish
inland waters and from the atmosphere that carries moisture above our heads.”20 Many
were sure that the day was not far distant before humankind tapped these waters. Utah’s
senator Frank E. Mossspoke of the need for the largest proposed distribution system in
the world—the North American Water and Power Alliance (NAWPA)—because he took
it for granted that water would be artificially engineered from the oceans.21
19 Udall speech, Congressional Record, 112 (January 29, 1966): 1488-90. 20 Floyd Dominy, An address before the annual Rivers and Harbors Congress Convention in Washington, D.C., June 1967, Congressional Record, 113 (June 21, 1967): 16708-09. 21 Senator Frank Moss, An address at the Conservation Congress for the Pacific Northwest, Wenatchee, Washington, March 7, 1967, Congressional Record, 113 (March 21, 1967): 7487.
In its early years, Project Skywater gave some reason for optimism such as when,
in 1968, the South Dakota School of Mines Institute of Atmospheric Science generated
evidence thatincreasingprecipitation overa non-mountainous areawas possible.22
Nevertheless, for all the talk of the future of rainmaking, the data to support claims or
provide irrefutable proof was not there. At first Reclamation engineers said, vaguely and
quite imprecisely, little more than that weather modification might augment water supply
in drought ridden areas or, conversely, prevent rainfall in flood-prone zones. Directly
correlating rainmakingefforts in the sky to water storage and distribution on the ground
was essential to winning support and situating rainmaking in the context of
Reclamation’s mission, but no one could say for certain how that correlation worked and
what the benefits were. Reclamation’s best guess was that weather modification in some
areas had the potential to increase surface water by 10-20 percent. In the Colorado River
basin alone they claimed cloud seeding could add two million acre feet to the Colorado
Even after several years into the project, all this seemed a long way off.
Nevertheless, a number of supporters of Project Skywater remained convinced that the
problem lay in the lack of government funding. But the project, like Johnson’s Great
Society,became a casualty of the Vietnam Warand shrinkinggovernment budgets. Even
still, expert coordination and liberal funding was unable to solve every problem. A
Skywater press release on March 17, 1968, reported the challenges the project faced.
Progress, while quite substantial, has served also to identify many problem areas which must be solved before operational capability can be achieved.
22 McGovern speech, Congressional Record, 114 (January 31, 1968): 1683. 23 Dominy speech, Congressional Record, 113 (June 21, 1967): 16709; McGovern speech, Congressional Record, 114 (January 31, 1968): 1683.
These areas include knowledge of—what atmospheric conditions are best suited for seeding, the amount of artificial nuclei required to achieve best results for given conditions. The behavior of nuclei inside real clouds, measuring and evaluating the effects of seeding, determining meteorological side effects, and the legal, social, biological, and other implications of precipitation management.24
Thus, by the late 1960s a shift occurred in the rhetoric praising the potential of
tapping the“rivers in the sky.” In the late 1950sScience Newsletterreported that in a
poll of meteorologists nearly half believed humans could prevent hail and lightning
within ten years and steer tornados and hurricanes within 50 years.25 They predicted no
less than total lordship over the elements in less than two generations. Years later the
scientists who held that view revised their thinking as they confronted studies and data
pointing to the highly unstable, unpredictable, and complex nature of weather. Moreover,
a sea of change in the basic assumptions of how water management operated washed over
the Reclamation’s operations. It was becoming clear that the best places to dam and
distribute water were running low; that the quest to control every western water system
alone was ineffective in solving the water crunch; that water managers must consider the
impact of their operations on ecosystems and the health of water systems and living
organisms. These new realities and societal assumptions began to chip awayat the
traditional enthusiasm for technology’s capacity to control nature. Not that the notion of
rainmaking was necessarily wrongheaded or technically impossible. Evidence suggested
that making rain or dispersing fog clouds was possible, but others schemes like steering
hurricanes were less probable. The disappointment and disillusionment of total control
24 Colorado River Basin Project Act, Remarks by Senator Frank Moss, Congressional Record, 114 (September 9, 1968): 26153. 25 de Florez speech, Congressional Record, 107 (April 3, 1961): 5434.
formed the basis of a new weather modification plan, more tempered and down-to-earth
than originally conceived.26
Even as scientists and policy makers acknowledged all that they did not know,
weather modification remained big business in the private sector and a preferred strategy
to confront the nation’s growing water crisis in public government. Reportedly, in 1965
seventy-nine weather modification projects operated in the United States and other
countries of the western hemisphere—sixty for rainmaking, the others for fog dispersal
and hail reduction. Private commercial firms seeded clouds for farmers, increased
snowpack above dams for power companies, abated hail for ranchers, and dissipated fog
In 1967 when Senator Peter H. Dominick of Colorado introduced legislation to
fund weather modification efforts in the upper Colorado River basin, he acknowledged
that “we have much to learn about the effect of weather modification upon ecology and
we must be equally aware of the legal ramifications.” Accordingly, he proposed twice as
much funding to study the results and effects of the program than for the practical
experimentation of weather modification. His plan attempted to complement Project
Skywater by enlarging the scope of research and direct application of increasing rainfall
and snowfall in the upper basin. Dominick and other politicians sympathetic to the idea
of increasing the nation’s water supply by cloud seeding frequently argued their case by
stating enough information existed to verify that weather modification was possible and
26 See Scientific Problems of Weather Modification, 3-4. 27 Halacy, Weather Changers, 4-5.
potentially beneficial, butthe project required sufficient funding to come to a satisfying
Technology, Testing, and Implementation Project Skywater had been designed to develop weather modification technology
and methods and to assist other entities working in the field. The project did not,
however, have thecongressional charter to extend beyond research and development to
operation and implementation. If state or county entities hoped to implement weather
modification in their locales, they had to fund it from state or county sources. Since none
of the research projects could extend indefinitely, and the fact that Reclamation had no
authority or funding to implement programs put the project on life support. Within three
decades of its first congressional appropriation, it had been discontinued.
The criticism that federally sponsored weather modifications never made it past
the drawing board was directed to, in Senator Dominick’s words, “a persuasive
bureaucratic attitude—in segments of both the government and academia—that it must
remain in the category of a research project—perhaps ad infinitum.” In the senator’s
1971 speech to his colleagues, he pointed out that twenty-five years of studyproduced
ample evidence that cloud seeding was feasible on a large scale. Instead, he claimed,
scientists “sit on cloud seeding as if it were some kind of illegitimate egg.” The senator
derisively referred to an “expert” from Reclamation who stated that “maybe by 1974” the
time was ripe to transition to actively using weather modification technology to fight
drought and other waterproblems.
28 “Colorado River Basin Legislation,” Remarks by Senator Peter H. Dominick of Colorado, Congressional Record, 113 (June 29, 1967): 18010; “S. 2826—Introduction of Bill Relating to Weather Modification,” Remarks by Senator Peter H. Dominick of Colorado, Congressional Record, 115 (August 12, 1969): 23526-27.
Dominick noted the rest of the world had taken weather modification seriously.
Russia annually spent millions to reduce hail and increase rain. Using the services of a
U.S. firm, in 1967 Iran ran an intense cloud seeding project and consequently brokea six
year drought. The same firm also aided Newfoundland’s chief forester to fight raging
forest fires and Cyprus to end a drought over a large portion of the island. All this
occurred at a time when the United States government sat on its hands. Dominick
blamed Congress for allotting only a small portion of the hundreds of millions of dollars
earmarkedto atmospheric research in the last quarter century to development of cloud
seeding technology. For instance, in fiscal 1971 eight agencies working on research and
development of cloud seeding shared only about $10 million. The senator urged
Congress to act on this issue to predict and prevent drought crises in the future.29
Skywater never provided the kind of national umbrella advocated by Dominick,
who in fact did not believe the program ought to be run by the Bureau of Reclamation
anyway. Rather, he saw the project was highly regional and local. When interested
parties convened at the Skywater Conference VII in Denver on March 2-3, 1972, the
unanimous decision was to keep itlocal and especially to divest as much local control of
individual projects as possible.30 Even still, Skywater was part of a national attempt to
collect in a systematic manner atmospheric data bytesting cloud seeding technology on a
local scale and evaluating it against broader patterns in weather behavior. To do this
required a sweeping program that drew on the latest technology and techniques
developed over the years.
29 Dominick speech, Congressional Record, 117 (August 6, 1971): 30626-28. 30 Archie M. Kahan, “Project Skywater – A Progress Report,” 11, http://wrri.nmsu.edu/publish/watcon/proc17/Kahan.pdf.
Reclamation’s Project Skywater was just such a program, and although modestly
funded in its first years it had become poised to lead the national effort. Project planners
usedthe latest technologysuch as acomputer-drafted cloud model that byinputting the
dimensions and characteristics of cloud formations was able to predict the behavior of the
cloud to modification stimuli. The model used atmospheric pressure, cloud height, air
temperature, and other variables to predict outcomes. Take for instance a cloud with a
radius of one kilometer in Amarillo, Texas. Given all the variables, the computer model
projected0.138 inches more rainfall if seeded than would ordinarilyfall under natural
Skywater featured a series of pilot projects across the western states to study
seeding in different environments at different times of the year. The earliest push in
cloud seeding was in winter cloud research. The Desert Research Institute in Nevada
headed Skywater’s first winter storm studies in the Sierra Nevada. The Institute used a
specially fitted plane, mountain-top radar, precipitation gauges, snow towers, and other
instruments and technology to understand the convective cloud system over the Sierra
Nevada and determine when and under what conditions it rained. Part of the program
was to test silver concentrations to show how dispersal of silver iodide makes its way into
the weather system in the air and the snow. The program lasted four seasons. The
Institute’s research at Pyramid Lake demonstrated, according to a Skywater report, that
“under optimum conditions—cloud seeding could add up to 129,000 acre-feet of new
water to the Truckee [River] annually.”32
31 Reclamation, Project Skywater: An Introduction to Rivers in the Sky, 3-4. 32 Desert Research Institute, University of Nevada System, Project Skywater: Final Report of the Desert Research Institute, July 1, 1968 to June 30, 1972, under contract for the Division of Atmospheric Water Resources Management of the Bureau of Reclamation, U.S. Department of the Interior, Reno, Nevada,
The largest winter cloud-seeding program was the Colorado River Basin Pilot
Project (CRBPP), beginning in the winter of 1970-71. In implementing this research
pilot project Reclamation was sensitive to state laws governing the use of weather
modification in Colorado. Back in 1951 the Colorado state legislature passed the
Weather Control Act, granting the state the right to claim increased snowfall from
weather modification activities. The Colorado Weather Modification Act of 1972
clarified the powers of the Department of Natural Resources, established an advisory
board, and required a permit and license for cloud seeding. Later, during the droughts of
the 1970s the state legislature appropriated funds to the Department of Natural Resources
for winter seeding programs to alleviate water scarcity in the state. Reclamation worked
with the state and relied on the expertise of other agencies and organizations in carrying
out the work. The Geological Survey supplied stream flow data; the National
Oceanographicand Atmospheric Administration and National Centerfor Atmospheric
Research provided special aircraft for studies; the Department of Transportation,
Colorado State Highway Department, and the Colorado Highway Patrol shared
information with avalanche researchers; and the Soil Conservation Service collected and
measured snow samples.33
The pilot program worked something like this. From field headquarters in
Durango, Colorado, project meteorologists determined the right conditions to fire up the
cloud seeding generators located at the base of the mountain slopes. Scientists in Denver,
using models, determined how wind currents lifted particulates from generators on the
1973, iv, 1; Gilbert Stamm, speech at the 27th Annual Nevada Water Conference held in Carson City, “Reclamation—1973 and in the Future,” Congressional Record, 119 (November 15, 1973): 37430-31. 33 U.S. Department of the Interior, Bureau of Reclamation, Division of Atmospheric Water Resources Management, Final Environmental Statement for Project Skywater, Denver, Colorado, 1977, 1-22–1-34.
ground into the storm clouds above. After the seeding, contractors hired by Reclamation
then collected data at over 200 monitoring sites to determine how much snowpack
accumulated as a result of seeding and whether increased snowpack might have an
impact on the ecology of the area and on avalanches. Scientists also examined how cloud
seeding affected natural processes and species, testing, for instance, soil samples to
determine concentration of silver from the cloud-seeding silver iodide.34
In general, Project Skywater had the blessing of locals. Some, however, worried
aboutimpactson snow levelsand avalanches, damages from heavy snowfall, costs of
snow removal, and other related issues. Residents from Telluride and Ouray and other
communities on the western slope worried about avalanche danger and other problems
associated with excess snow. They were concerned about the effects of snow and runoff
on hunting, fishing, jeeping, agriculture, and ranching. The anxiety was so high that one
miner even threatened sabotage, saying, “If those weathermen screw up life around here
they may suddenly discover their equipment blown to bits.” A man from Silverton,
Colorado, commented that regardless of the actual resultsof Skywater, Reclamation may
shoulder the blame for weather accidents. Reclamation officials like Archie Kahan, chief
of Reclamation’s office of atmospheric water resources in Denver, countered these
criticisms by attempting to assure locals that the bureau was makingeveryeffort to study
the ecological, social, and economic impacts of cloud seeding before implementing a
34 Colorado Department of Natural Resources, Snowpack Augmentation Research Needs: A History of Weather Modification in Colorado, Bureau of Reclamation Cooperative Agreement No. 9-07-85-V0027, Denver, Colorado, June 1982, 1-3; U.S. Department of the Interior, Bureau of Reclamation, Mountain Skywater: The Story of the Colorado River Basin Pilot Project in the San Juan Mountains of Southwestern Colorado, VHS, Reclamation, [no date]. 35 Roger Rapoport, “Some Tough Westerners Say: ‘No Snow Job for Us!’” Sports Illustrated, (June 29, 1970), online.
In the end, no long-term weather project was established in the Colorado River
basin, despite the generally positive conclusion that seeding from 20 to 40 percent of the
winter storms and that over halfof those yieldedhigher precipitation.36 Thepilot project
in the Colorado River basin was one piece of a puzzle spread across the western states.
Project engineers and researchers developed or planned to develop technology and
smaller winter cloud seeding projects in Montana’s Bridger Range, Utah’s Uinta
Mountains, New Mexico’s Jemez Mountains, California’s Sierra Nevada, and
Wyoming’sMedicine Bow Mountains.37
Reclamation had high hopes that the Sierra Cooperative Pilot Project in the
American River basin would bring together the latest technology to direct the possibilities
of atmospheric water management in the Sierra Nevada. Armed with the mission to find
a safe and clean way to enrich the area’s natural precipitation, Reclamation began by
collectingenvironmental data. The Center for Regional Environmental Studies at
California State University in San Diego received the contract to review the
environmental effects of the project. Together with the Forest Service the project
eventually produced a report situating weather management into the larger ecological
picture: soil water, plant growth, steam and lake biota, and animal migration.38 The
project aimed to developtechnology to predict thenature and cloud-seeding potential of
winter clouds; evaluate when to seed, potentially to avoid contributing to avalanche or
flooding danger; uncover potential legal, economic, and social consequences of cloud
seeding. However, the project never made it past planning and was never carried out.39
36 Kahan, “Project Skywater,” 8. 37 Reclamation, Final Environmental Statement for Project Skywater, 1-19; Kahan, “Project Skywater,” 13. 38 Reclamation, Final Environmental Statement for Project Skywater, 1-18–1-19, 1-20 –1-21. 39 Reclamation, Final Environmental Statement for Project Skywater, 1-20–1-21.
As winter cloud seeding research progressed, Project Skywater initiated a few
summer cumulus seeding research projects. Archie Kahan stated that summer projects
came “because many key problems remain in summer cumulus seeding and there is an
apparent rapid increase in public interest in summer seeding.” The summer cloud
seeding projects spread across the country. Research programs at the Institute of
Atmospheric Sciences at South Dakota School of Mines and Technology examined salt
and silver iodide in summer convective clouds. Skywater’s San Angelo Cumulus Project
near San Antonio, Texas, developed use of hygroscopic seeding to increase precipitation
in warm climates. In Illinois the state water survey teamed up with Skywater to develop
technology on frontal and squall-line storms. Skywater also worked with the governors
of Arizona, Texas, and Oklahoma and with the President’s Office of Emergency
Preparedness for drought-relief cloud seeding operations. Cloud seeding reportedly
produced increases in rainfallof10-15 percent in Texas and Arizona and of95,000 acre
feet in Oklahoma—strong evidence that further developments and research in the field
could result in large-scale benefits.40
The largest summer seeding program was the High Plains Cooperative Program, a
research-driven field program designed to develop rainmaking technology for use on the
high plains. Reclamation established threefield sitesnearMiles City, Montana, Colby
Goodland, Kansas, and Big Spring-Snyder, Texas, where testing began in May 1975.
The program used some ground generators, like the CRBPP, and also airplanes to seed
the cumulus clouds with silver iodide and urea-ammonium nitrate. The planes were
specially equipped to monitor temperature, winds, humidity, and cloud updrafts.
Although theplanesseeded areasno larger than aradius of 65 miles from the radar 40 Kahan, “Project Skywater,” 8, 11-12.
control station at each field location, the effects of that seeding might extend across a
broad geographical area. This was one of the challenges of analyzing and evaluating
The program collected as much data as possible. Field teams monitored clouds
suitable for seeding, examined when and under what conditions seeding was applicable
using complex numerical models and hypotheses, and developed seeding techniques
appropriate to atmospheric conditions. Then, scientists evaluated the data. Just a few
years into the program scientists had collected essential atmospheric data on convective
rain cells and the percentage of cells acceptable for seeding. To be more precise, of the
20,000 convective cells expected to accumulate in the atmosphere during the five-month
summer season, 800 appeared suitable for seeding.42
From the beginning of Project Skywater the concern was how cloud seeding
might affect “the balance of biological communities,”in the words of theNational
Science Foundation.43 Reclamation initiated ecological studies such as the Uinta Ecology
Project in Utah and the San Juan Ecology Project in Colorado and in some cases
produced environmental impact statements for its Skywater projects. The challenge, of
course, was that impacts to land, water, and air were not site specific. The size and
complexity ofweather systemsmade the task of determiningenvironmental
consequences highly difficult and imprecise.
There were also questions about a dark side of cloud seeding. Some wondered if
cloud seeding caused, or at least contribute to, the torrential flood that ripped through 41 Reclamation, Final Environmental Statement for Project Skywater, 1-6–1-14. 42 Reclamation, Final Environmental Statement for Project Skywater, 1-12–1-14. 43 U.S. Department of the Interior, Bureau of Reclamation, An Overview of the Skywater IX Conference on Precipitation Management and the Environment: Discussion and Summary Reports, Denver, Colorado, September 1977, 1.
South Dakota’s Rapid City in the summer of 1972. During the evening of June 9, Rapid
City residents thought little of the rising waters. Near midnight, however, the river tore
up Canyon Lake dam—the last defense—and the waters that had been building strength
all day laid waste to the city, claiming 250 lives and $100 million in property damage.
What was to blame for this catastrophe? Was it an act of nature or, as on one writer
called it, an “‘Act of God’—with a Few Grains of Salt?” Could the Institute of
Atmospheric Sciences at the South Dakota School of Mines and Technology’s Project
Cloud Catcher, funded byacontract awarded byReclamation, have beenresponsible for
producing rain “at an unusually heavy pace?” The director at the Institute of
Atmospheric Sciences denied any wrongdoing, and even a board of inquiry established
by the governor concluded that cloud seeding did not contribute to the disaster. One
article called into question conclusions weather modification scientists that there was no
connection. Ironically,they simultaneously acknowledgednot knowing enough about the
weather system to definitely say how and when rainmaking works. James Crutchfield, an
economist at the University of Washington, stated, “When it gets to the point where there
is a possibility of really catastrophic side effects, and when these catastrophic side effects
are occurring close enough to the weather modification as to raise the possibility of a
cause-and-effect relationship, there is serious questions in my mind as to whether we
ought to be fooling around with it at all.”44
Another problem with cloud seeding is the chemical, silver iodide, an inorganic
compound that can be toxic when ingested. According to one report, even at low
concentrations dispersed over a large area the agent might have negative consequences to
44 For details on the debate over the causes of the Rapid City flood, see “The Effects of Weather Modification,” Congressional Record, 119 (May 31, 1973): 17628-34; quote by Crutchfield, Ibid., 17633.
freshwater microorganisms. Moreover, there was always a question of silver
accumulating in the atmosphere, plants, or the groundwater if cloud seeding became
widely practiced. A law professor in Arizona reportedly warned of the legal
ramifications stemming from pumping silver into the atmosphere—in however small
amounts. However, the workshop uncovered nothing incriminating. “There appears to
be no real threat from sliver iodide as a cloud seeding agent…. Public concern is probably
based on misunderstanding, not on actual damages.” Despite the assurance, it
recommended monitoring concentrations and left room for revision based on future
Reclamation’s environmental statement noted adverse effects in tentative terms.
Avalanches might occur, elk ranges could diminish, cropland may become subject to
erosion, but concluded nothing was certain to warrant immediate concern. It was this
tentativeness, this inconclusiveness, that had defined the project—not just the impact to
the environment but the very efficacy of the project itself.
To be sure, Skywater brought complex technical and technological issues to bear
on the question of altering the weather. The project required sophisticated statistical
designs, data collection, measurement, communications, field support and equipment,
analysis, and cooperative agreement between state and government agencies and the
public. It required adjusting variables in each area and considering the nature of the
atmosphere and other site-specific conditions over a broad geographic canvas. Skywater
consisted of many parts, seemingly disparate, spread across the western states. Project
Skywater designers hoped to integrate technologies and methods developed across the
45 Reclamation, Overview of Skywater IX Conference, 1-2, 13, 15.
region into a national effort, but this was not to be. Moreover, Skywater never received
the funding or congressional blessing that some supporters had hoped.46
Conclusions After 1940 some scientists and lay persons used the word “control” when
speaking of the possibility of changing the weather. Some optimistically believed that it
was possible to tinker with the weather system—to increase precipitation, disperse fog,
steer hurricanes, etc. The idea of Project Skywater derives from the human impulse to
modify the natural world to its own liking. When the technology and means became
available to tinker with the weather system, it was as though an infusion of adrenaline
shot into the scientific and meteorological communities. At long last the primal urge to
harnessand control rain, snow,hail,fogand even hurricanes seemed within reach.
Skywater was an ambitious program that if seemingly fantastical today evoked in the Age
of Engineering a certain inevitable and climatic drama.
If Project Skywater and other like projects teach us anything it is that human
control of the atmosphere—nature, for that matter—is not as total as we sometimes think
possible. No sooner had meteorologists, policymakers, and agriculturalists set out on the
course of weather control than they confronted the immensity of the situation. The
weather system was just too large. U.S. scientists in Project Stormfury tested methods to
steer or disperse the energy in hurricanes, but by 1980 they had given up the quest.
Dropping a bomb in the ocean to break up the storm would “be like trying to stop a
freight train by placingafeather on the tracks,” according to one observer. Layering the
46 James V. Lunsford, “Water Potentials of Weather Modification,” Paper delivered at the New Mexico Water Conference, March 27-28, 1969, 77, http://wrri.nmsu.edu/publish/watcon/proc14/Lunsford.pdf. Reportedly, in 1990 the project received a small infusion of funds $3.2 million, but by that late date the project had already nearly expired, see Congressional Record, 136 (June 19, 1990): 14621.
ocean with a film to prevent moist air from rising and forming storms might work if the
ocean were not so big and were it possible to predict where storm clouds developed.47
Simply, nature is too bigand too complex to control. Modified, perhaps, or managed, but
even then not entirely to our liking. In fact, about the only method proven successful, at
least to some extent, is cloud seeding to increase precipitation.
Project Skywater’s history overlapped an important transitional period in
Reclamation’s history. It came as Reclamation entered an era of huge construction
programs and builtdams on manymajor river systemsin the West and,when under
Floyd Dominy, Reclamation enjoyed a reputation and elevated position within the
pantheon of the federal bureaucracy. That the bureau took the next step in its institutional
progression and turned to domination over the “rivers in the sky” should come as no
surprise. By the late 1960s, the consensus that supported big dam construction had
waned, and scientists temperedtheir optimism in weather modification possibilities. The
United States was entering a new era of resource management, and that had a tremendous
impact on Reclamation’s operations. By the time it had thoroughly transitioned from
dam builder to water manager, in the late 1980s, Reclamation no longer entertained
notions of total domination over the West’s water resources—not on ground nor in the
While scientists have faced the fact that the processes involved in rain formation
are complex, not all have given up the quest to alter the weather. Recently, Roelof
Bruintjes, of the National Center for Atmospheric Research in Colorado, commented that
better monitoring and measuring technology may lead to developments in rainmaking.
47 Jack Williams, “Project Stormfury Attempted to Weaken Hurricanes in the 1960s and 70s,” USA Today, April 18, 2006, online.
Even now, according to one account, there are more than 150 cloud seeding projects in
forty countries. In China the China Meteorological Administration (CMA) oversees a
major ongoing effort using anti-aircraft cannons to bombard the skies with silver-iodide
particles. The Chinese government claims the $100 million per year project created 250
billion metric tons of artificial rain over a seven-year period, but these figure cannot be
verified. China is one of many countries that use weather modification, however
scientifically suspect, to alleviate challenges related to crop damage from hail or from
severe water shortages.48
All this continues to be met with skepticism by some in the scientific community
who insist that however far we have come in altering the weather, the dream is still a long
ways off. Would-be weather changers must confront scientific, ethical, cost-benefit, and
various questions if they are to make progress where Project Skywater and other early
projects began. Project Skywater played no small role in the ongoingeffortby producing
a large body of experimental data for the field of meteorology and inching us closer to the
possibilities and limitations of altering the weather.
48 Rob Sharp, “Weather Modification: The Rain Makers,” The Independent, April 30, 2008.
Colorado Department of Natural Resources. Snowpack Augmentation Research Needs: A History of Weather Modification in Colorado. Bureau of Reclamation Cooperative Agreement No. 9-07-85-V0027. Denver, Colorado, June 1982.
Desert Research Institute/University of Nevada System. Project Skywater: Final Report of the Desert Research Institute. July 1, 1968 to June 30, 1972. Under contract for the Division of Atmospheric Water Resources Management of the Bureau of Reclamation, U.S. Department of the Interior. Reno, Nevada, 1973.
National Academy of Sciences, National Research Council. Scientific Problems of Weather Modification; A Report of the Panel on Weather and Climate Modification. Publication 1236. Washington, D.C.: National Academy of Sciences, 1964.
United States Congress. Congressional Record. 1951-90.
United States Department of the Interior, Bureau of Reclamation. The Design of SCPP-1, Sierra Cooperative Pilot Project. Denver: Office of Atmospheric Water Resources, August 1982.
United States Department of the Interior, Bureau of Reclamation. Final Environmental Statement for Project Skywater. Three Volumes. Denver, Colorado, 1977.
United States Department of the Interior, Bureau of Reclamation. Mountain Skywater: The Story of the Colorado River Basin Pilot Project in the San Juan Mountains of Southwestern Colorado. VHS, Bureau of Reclamation, [no date].
United States Department of the Interior, Bureau of Reclamation. An Overview of the Skywater IX Conference on Precipitation Management and the Environment. Denver, Colorado: September 1977.
United States Department of the Interior, Bureau of Reclamation. Project Skywater: An Introduction to Rivers in the Sky. December 1973.
United SstatesDepartment of the Interior, Bureau of Reclamation. “Project Skywater: A Project Report.” By Archie M. Kahan, Chief of Division of Atmospheric Water Resources Management, Engineering and Research Center, Reclamation, [1972?]. Available on the web at http://wrri.nmsu.edu/publish/watcon/proc17/Kahan.pdf.
Halacy, D. S., Jr. The Weather Changers. New York: Harper & Row, Publishers, 1968.
Hemel, Eric I., and Clifford G. Holderness. An Environmentalist’s Primer on Weather Modification. Stanford, California: Stanford Environmental Law Society, September 1977.
Lamar, Howard R., editor. The New Encyclopedia of the American West. New Haven, Connecticut: Yale University Press, 1998.
Rapoport, Roger. “Some Tough Westerners Say: ‘No Snow Job for Us!’” Sports Illustrated. June 29, 1970. Online.
Sharp, Rob. “Weather Modification: The Rain Makers.” The Independent. April 30, 2008.
Spence, Clark C. The Rainmakers: American “Pluviculture” to World War II. Lincoln: University of Nebraska Press, 1980.
Williams, Jack. “Project Stormfury Attempted to Weaken Hurricanes in the 1960s and 70s.” USA Today. April 18, 2006. Online.
Lunsford, James V. “Water Potentials of Weather Modification.” Paper delivered at the New Mexico Water Conference, March 27-28, 1969. Available on the web at http://wrri.nmsu.edu/publish/watcon/proc14/Lunsford.pdf.