Visual Timeline

1800 American Indians

For centuries, American Indians migrate through the Columbia Basin to hunt and fish. The Wanapum establish campsites and villages in the Hanford area.

Wanapum fishing at Celilo falls Wanapum village

1850 Washington Territory and the first white settlers

Washington Territory becomes part of the United States in 1846. Americans, mostly farmers, begin settling in the area which is now the Hanford Site around that time. Over the next decades, they build the town of White Bluffs.

Town of White Bluffs

1889 Washington becomes a state

Washington gains representation in Congress.

1905 e=mc2

In Switzerland, Albert Einstein publishes an influential paper on mass-energy equivalence. A series of discoveries in physics—including the discovery of the neutron by James Chadwick in 1932 and the work of Enrico Fermi, Leó Szilárd and others on nuclear fission—will lead to the theoretical possibility of an "atom bomb."

1907 Hanford, Washington

The small town of Hanford, after which the Hanford Site is named, is founded. Some of its buildings still exist today.

Town of Hanford

1939 The Einstein-Szilárd letter and the Manhattan Project

Worried that Nazi Germany is developing atomic weapons, scientists send a letter to President Roosevelt advising him to begin a program to develop such weapons first. A coordinated government effort begins to investigate the possibility of building an atom bomb. When the project's headquarters moves to Manhattan, it becomes known as the Manhattan Project.

1941 The United States enters World War II

On December 8, 1941, one day after the Japanese attack on Pearl Harbor, the United States declares war on Japan.

1942 Hanford is chosen for the war effort

Under the command of Lieutenant General Leslie Groves, officials at the Manhattan Project have been looking for a place to build a nuclear reactor. It has to be somewhere far from major cities, and it has to be near a major source of water. For defense purposes, it can't be too near the coast. The site has to have access to a robust source of electricity, something like Grand Coulee Dam. Late in 1942, officials identify a location on the Colubmia River.

1943 Building starts on the Hanford Site

Everyone in the 670 mi2 Hanford Site is evacuated, including American Indians. The towns of White Bluffs and Hanford are emptied. About 30,000 skilled and unskilled workers are brought to the site in the first year, constructing buildings and machinery with incredible rapidity. That number will eventually swell to 50,000. Most live in temporary barracks, but many are housed in the nearby town of Richland (previous pop. 300). Almost no one knows the actual purpose of their work; the goal of all this construction is a secret. At this time, the site is run by the Army Corps of Engineers; the main contractor is DuPont.

Hanford construction camp D Reactor construction

1944 The first reactor begins production

B Reactor, the world’s first experiment in large-scale nuclear fission, begins producing plutonium.

B Reactor B Reactor

1945 Plutonium processing begins

T Plant, which had started construction in 1943, goes operational. Because the plutonium produced by B Reactor is mixed with uranium, it is necessary to chemically extract it in facilities like T Plant. Dissolving the fuel rods in chemicals in order to extract plutonium generates large amounts—eventually millions of gallons—of highly radioactive liquid waste. The long-term dangers of this waste only later become clear.

1945 The first atomic detonation

In a test code-named Trinity, the U.S. army sets off a bomb near Alamogordo, New Mexico made from Hanford's plutonium. The blast is equivalent to 20 kilotons (40,000,000 pounds) of TNT.

1945 The Hiroshima bomb

An atomic bomb called "Little Boy," made with enriched uranium from the Manhattan Project facility at Oak Ridge, Tennessee, is dropped over the Japanese city of Hiroshima to devastating effect.

1945 The Nagasaki bomb

President Harry Truman makes the decision to drop a second bomb, this one named "Fat Man," on the city of Nagasaki. This one is made with plutonium from the Hanford Site. At Hanford, it has finally been revealed what everyone has been working on; a local newspaper headline reads "IT'S ATOMIC BOMBS." The decision to bomb Nagasaki is and will remain controversial—was it really necessary?—but the controversy largely passes Hanford by. A local high school will later go on to adopt the insignia of a mushroom cloud.

Mushroom cloud over Nagasaki Richland Villager headline

1946 The Cold War begins

A period of political conflict between the United States and the Soviet Union begins that will last until 1991. At times, the two countries seem on the very brink of war. Because the Soviets soon develop their own nuclear weapons, plutonium production at Hanford expands in order to produce more warheads.

1963 N Reactor goes online

N Reactor is the last plutonium-producing reactor to be built at the Hanford site. It is also the only one to simultaneously produce electricity. As the only reactor of its kind, it is important enough that President Kennedy attends when its operations officially begin.

JFK speaks at N Reactor

1976 The RCRA

The Resource Conservation and Recovery Act becomes law. It is one of the main pieces of legislation that will affect cleanup operations at Hanford; it governs hazardous waste disposal.

1976 The HWMA

The Hazardous Waste Management Act is a Washington State law similar to RCRA; in the interest of protecting the environment and Washington citizens, it restricts the ways that hazardous waste can be disposed of.

1977 Department of Energy becomes lead agency

The Department of Energy becomes the main government agency that operates the Hanford site, a position it continues to hold in the present day. Previous agencies included the Army Corp of Engineers, the Atomic Energy Commission, and the Energy Research and Development Administration.


The Comprehensive Environmental Response, Compensation, and Liability Act is a federal law that provides for the cleanup of sites containing hazardous materials.

Major Facilities (Years of Operation)

[SVG/VML Graphic pending]

B Reactor
D Reactor
T Plant
B Plant
F Reactor
H Reactor
DR Reactor
C Reactor
REDOX (S Plant)
K West Reactor
K East Reactor
N Reactor

The current era of cleanup begins

In 1989, the DOE, EPA, and Washington State Department of Ecology agree to cooperate on cleanup at Hanford. The document formalizing this relationship is the Tri-Party Agreement. The agencies of the Tri-Party Agreement plan to address the environmental problems created by decades of plutonium production at the Hanford Site.