The park consists of three units: one in Oak Ridge, Tennessee, one in Los Alamos, New Mexico and one in Hanford, Washington.

For over ten years, the DoE worked with the National Park Service and federal, state and local governments and agencies with the intention of turning places of importance into a National Historical Park.

After several years of surveying the three sites and five other possible alternatives, the two agencies officially recommended a historical park be established in Hanford, Los Alamos and Oak Ridge.

There are three areas of the park located on Los Alamos National Laboratory property.

These locations are only open to the public by special bus tours organized by the Department of Energy: The American Museum of Science and Energy provides bus tours of several buildings in the Clinton Engineer Works including the: