Nuclear Blasts in Mississippi

by Stephen Cresswell / August 2008

At 10:00 a.m. on October 22, 1964, the United States government detonated an underground nuclear device in Lamar County, in south Mississippi.  Residents there felt three separate shocks, and watched as the soil rose and behaved like ocean waves.  Hunting dogs howled in terror, and two miles from the test site the blast shook pecans off the pecan trees.  This nuclear test, and the one that followed two years later at the same Mississippi site, were the only nuclear explosions on U.S. soil east of the Rocky Mountain states.

Atomic bombs were in the news in October 1964.  Only one week before the Mississippi nuclear test, newspapers had reported that Communist China had detonated its first atomic bomb.  For residents in Lamar County, however, no news story was watched more closely than the plans for nuclear testing in Mississippi.

Background of Nuclear Testing

The world’s first nuclear test came during World War II at Alamogordo, a remote location in the New Mexico desert on July 16, 1945.  Three weeks after this successful test, the United States dropped two nuclear bombs on Japan, one over Hiroshima and one over Nagasaki, killing some 220,000 residents of those cities and leading to Japan’s surrender.  President Harry S. Truman defended his decision to use nuclear bombs by saying that he hoped the bombs would convince Japan to surrender.

Ironically, after World War II was over, the United States became allied with its former World War II enemies, but became locked in a bitter Cold War with its former World War II ally, the Soviet Union.  Four years after America’s first testing of a nuclear device, the Soviets tested their first bomb.  In the coming years, the United States built some 70,000 nuclear warheads, and the Soviet Union vowed to build a similar number.  By the time of the nuclear testing in Mississippi in 1964, Great Britain, France, and China had joined “the nuclear club.”

As a part of the rivalry between Communist and non-Communist nations during the Cold War, nuclear experts developed new types of nuclear weapons, and insisted that it was necessary to test these new designs.  Many citizens around the world, however, expressed concern that such testing would lead to medically harmful “fallout” — radioactive particles that would drift to earth and enter people’s bodies, potentially causing leukemia and other diseases. In 1963, the United States, Great Britain, and the Soviet Union signed a Partial Test Ban Treaty, agreeing not to test nuclear devices in the atmosphere or under water. The treaty did not address underground testing, because of disagreements and uncertainty over how to verify that nations were not testing weapons underground.

Project Dribble

A number of nuclear testing experts said it was not a good idea to prohibit underground testing, because some nations might cheat by secretly testing nuclear weapons underground.  In most cases, seismographs (the device used to measure earthquakes) could detect underground nuclear tests.  The United States wanted to know more about underground testing and how it could be detected, and designed Project Dribble, which included the two Mississippi detonations, to investigate the possibility that cheating nations could hide their underground tests in some way.

Nuclear scientists investigated several potential test sites in Mississippi, but finally selected a site just north of Baxterville in Lamar County, about 28 miles southwest of Hattiesburg.  Geologically, the area was called the Tatum Salt Dome, a vast supply of dense salt located about 1,000 feet below ground level. Salt domes deep beneath the surface of south central Mississippi are the dried remains of a sea that covered much of the state in the Mesozoic Era.  The plan was to detonate one nuclear bomb about 2,700 feet down, in solid salt.  This would be the 1964 blast, code-named Project Salmon.  It was believed Project Salmon would blast a huge cavity in the salt.  Then the second blast, Project Sterling, would involve detonating a smaller nuclear bomb inside the cavity left in the salt by Project Salmon.  Scientists believed that because the bomb would be detonated in a cavity rather than in solid rock, the shock waves would be muffled and the test might not be detectable by seismographs and other measuring devices.

So in 1964 officials of the Atomic Energy Commission came to Mississippi and began preparing the Tatum Salt Dome site for Project Salmon.  A hundred Lamar County residents found work at the site, primarily driving trucks and heavy equipment, or providing food for the project employees.  The nuclear test was scheduled for September 22, 1964, but the wind direction was not right until October 22.  On that date about 400 residents were evacuated from the area, and were paid $10 per adult and $5 per child for their inconvenience.  The zone from which citizens were evacuated stretched five miles downwind of ground zero, and about half that distance in directions that were not downwind of the test. Click here to see the Mississippi segment from the Peter Kuran film “Atomic Journeys.” (YouTube site accessed July 2008.)

Most residents later reported that the shock of the explosion was much stronger than they had been led to believe.  The editor of the Hattiesburg American, although almost thirty miles away, reported that he felt the newspaper building sway for nearly three minutes.  At the test site, creeks ran black with silt-laden water, and by seven days after the blast, more than 400 nearby residents had filed damage claims with the government, reporting that their homes had been damaged or that their water wells had gone dry.

Horace Burge lived about two miles from the site of the explosion, and returned home to his three-room house to discover considerable damage caused by the blast.  The fireplace and chimney were badly damaged, and bricks littered his living room.  Broken dishes and jars were all over his kitchen floor, and the shelves fell down inside his refrigerator and broke several glass containers.  His electric stove was covered with ash and pieces of concrete.  The pipes under his kitchen sink had burst, leading to flooding inside the house.

Within days, the United States government began reimbursing local residents for the damage done to their homes.  After the blast, reporters from the Hattiesburg American interviewed many local residents who said they didn’t want this nuclear testing to be done in their neighborhoods, but who added that there was nothing they could do about it. In an editorial, the Hattiesburg American lectured its readers that such tests were necessary for the future security of the United States.

After seismic analysis, the government scientists reported that Project Salmon had been a success, with the bomb delivering the same force as 5,000 tons of TNT.  The Project Salmon blast was about one-third as powerful as the bomb that destroyed Hiroshima in 1945.  The bomb blasted a void in the salt as predicted, a spherical cavity that was about 110 feet in diameter.

The Project Sterling blast, on December 3, 1966, was considerably weaker than the blast two years earlier, as it was intended to be.  Instead of the force of 5,000 tons of TNT that Project Salmon had developed, Project Sterling’s bomb had the force of 350 tons of TNT.  Observers two miles away from the blast reported they barely felt a bump.  Like Project Salmon, Project Sterling was labeled a success.  Because it was detonated in a cavity in the salt, its force, as measured by seismographs, was about 100 times weaker than would have been expected with the same sized bomb placed in solid rock or salt.  Thus U.S. government officials reported that Mississippi’s two nuclear blasts, as a part of Project Dribble, helped prove that in fact the seismic effect of a nuclear blast could be greatly reduced if such a blast were set off in a large cave.  This suggested it might be possible for a nation to cheat on a future nuclear test ban by hiding a nuclear test.  It also helped teach atomic scientists how to detect and measure such hidden blasts.

Though Mississippi’s part in nuclear testing was over by 1966, the Tatum Salt Dome site did see two additional tests by the Atomic Energy Commission as a part of Project Miracle Play. Project Miracle Play was similar to Project Dribble in that it too was designed to detect underground testing, but this time the two blasts were conventional bombs instead of nuclear.  Mississippi’s two explosions in Project Miracle Play in 1969 and 1970 were fueled by a mixture of oxygen and methane.

After the 1960s

Since the 1960s, much has changed. The United States has reduced its nuclear stockpile considerably, to about 10,000 warheads, and Britain and France have also reduced their stockpiles.  The Cold War has ended, and few nations remain Communist.  The former Soviet Union split apart, and the nation of Russia inherited the nuclear warheads that formerly belonged to the Soviet Union.  These Russian nuclear stockpiles are considerably smaller than those during the height of the Cold War.  The United States has not tested a nuclear weapon since 1992, and the other major nations of the world have also gone years without nuclear testing, or planning any nuclear tests for the future. 

On the other hand, the United States expresses concern that nations such as Iran might soon develop and test nuclear weapons, or that a terrorist group might turn to nuclear warfare, including possibly a conventional bomb that would spread radioactive material.  Further, North Korea claims to have detonated a nuclear bomb in 2006, though some claim this small explosion was not really a successful nuclear test. And, in July 2008, the International Atomic Energy Agency reported that North Korea had shut down its nuclear weapons-making nuclear reactor. Aside from the possibility that the enemies of the United States might obtain nuclear weapons, many citizens express concern that even if new nations, or groups, do not develop nuclear weapons, the world will always be in danger of nuclear explosions because 36,000 atomic bombs still exist.

Health and safety at Tatum Salt Dome

With any nuclear test there is the danger of health problems developing among the people and other living things near the test site.  At the Mississippi nuclear test site, one fear in 1964 was that these underground explosions would “blow out” during the tests, sending dirt, gasses, and radioactive material high into the air.  Government officials said this was unlikely, pointing out that the 2,700-foot shaft had been filled with gravel and an enormous concrete plug.  After the 1964 blast, scientists reassured Mississippians by reporting that all radiation had been contained underground.  They said the soil, water, and air in the area was not made radioactive.

Unfortunately, the site did become contaminated after the blast.  Two months after the 1964 test, nuclear researchers drilled a hole down into the void left by the blast in order to lower instruments into the cavity.  In drilling the hole, the drill bit brought radioactive soil and water up to the surface.  The same thing happened in 1966.  Several times the U.S. government came in to attempt to clean up the Tatum Salt Dome site.

In 1972, buildings at the site were bulldozed and sent to the government’s Nevada Test Site, where considerable radioactive material was already in storage. Most of the other radioactive material at the Tatum Salt Dome site (primarily soil, rock, and water) were put back down into the test cavity, where it remains today in solid or sludge form.  Some of the radioactive liquids were injected into “Aquifer Number 5,” a vein of salty water located about 2,500 feet underground at the Tatum Salt Dome site.  U. S. government officials erected a large stone monument at the site, with a brass plaque warning future generations not to drill or dig in the vicinity of this test site.

Some Lamar County residents complained of lingering health effects in the decades after the blast.  Some argued that the number of cancer deaths in the Tatum Salt Dome area is higher than national averages. Federal officials maintain that there is no health risk associated with living near the Tatum Salt Dome site, but the government did pay at least one former Mississippi employee of Project Dribble for unspecified health damages. Around 2000, the government built a water pipeline to help residents near the Tatum Salt Dome get drinking water from far away from the test site, in hopes of calming residents’ fears about their drinking water.

On to the future

Most Lamar County residents have already forgotten Mississippi’s two nuclear explosions, and younger citizens of Mississippi typically have never heard of Project Dribble.  The debate about the future of nuclear weapons, though, will continue.  Many people will argue that nuclear weapons are an important part of a diversified defense strategy for the nations that possess them, while others believe that nuclear weapons make the world a very unsafe place, with the potential to wreak tremendous harm to the environment and to end human society as we know it.

Stephen Cresswell, Ph.D., is professor of history at West Virginia Wesleyan College and the author of an earlier Mississippi History Now article, “Was Mississippi a Part of Progressivism?” He is the author of Rednecks, Redeemers, and Race: Mississippi after Reconstruction, 1877-1917, a book in the Mississippi Historical Society’s Mississippi Heritage Series.

  • Map showing nuclear testing site in Mississippi
    Location of nuclear tests site in Mississippi. Map courtesy the U.S. Department of Energy.
  • Atomic Energy Commission's Vermillion
    Henry G. Vermillion, office of information director, U.S. Atomic Energy Commission, indicates evacuation area for the 1964 nuclear test site. Moncrief Photograph Collection, Item #180, Mississippi Department of Archives and History.
  • Residents prepare homes for nuclear blasts
    Some residents stabilize chimneys, porches, and outbuildings in anticipation of the blast. Moncrief Photograph Collection, Item #197, Mississippi Department of Archives and History.
  • Crowd gathers for Mississippi nuclear testing
    Crowds gather a distance from the Tatum Salt Dome nuclear test site on October 22, 1964. Moncrief Photograph Collection, Item #183, Mississippi Department of Archives and History.
  • Nuclear test shakes, rattles and rolls nearby homes
    Horace Burge, who lived about two miles from the site, came home after the Salmon test to find shattered dishes, and a damaged fireplace and chimney. Moncrief Photograph Collection, Item #261, Mississippi Department of Archives and History.

Selected Bibliography


The chief sources for this article were issues of the Hattiesburg American from the fall of 1964 and the late fall and early winter of 1966.  Also consulted were issues of the The New York Times and The Washington Post from the same time period.

James W. Crawley, “The Day We Nuked Mississippi,” Waynesboro, Virginia, News Virginian, July 11, 2005. (Accessed July 2008) This syndicated article appeared in many other newspapers nationwide.


Two books provide excellent background reading on early nuclear testing in the United States:

Boyer, Paul.  By the Dawn’s Early Light.  Chapel Hill: University of North Carolina Press, 1994.

Miller, Richard L.  Under the Clouds: the Decades of Nuclear Testing.  Woodlands, Texas: Two Sixty Press, 1999.

Websites (the three sites were accessed July 2008)

Catalog of Worldwide Nuclear Testing
Salmon, Mississippi Site, United States Department of Energy
Salmon and Sterling Nuclear Detonation Test Site