Mound Laboratory & the Dayton Project - Our Slice of the Oppenheimer Story
Did you know that the Great Miami Riverway has its own slice of this atomic cold war history? Have you heard about the Dayton Project, or the Mound Laboratory in Miamisburg?
On July 21st, movie-goers rushed to their local theaters to catch the new Oppenheimer film, doubling its projected box office performance for opening weekend around the globe. Film critics are praising this piece as a spectacular achievement in storytelling.
Many who live around the Great Miami Riverway are less familiar with the Mound Laboratory that was located in Miamisburg. Named for the neighboring Adena Mound—one of the two largest conical mounds in eastern North America—this government facility revolutionized Cold War, Nuclear Age, and Space Race history.
Construction of the Mound facility began in 1946 to support the Manhattan Project (the secret atomic project that Oppenheimer was recruited to be a part of in 1942). The Dayton Project (and the Mound facility specifically) was a research and development project to produce polonium during World War II, as part of the larger Manhattan Project to build the first atomic bombs. Early work at the site involved production of polonium-beryllium initiators used in atomic weapons and research related to radionuclides and detonators. In the 1950s, the facility manufactured a variety of nuclear weapons parts, including cable assemblies and explosive detonators, and electronic firing sets. The Mound operated from 1948 to 2003 and at its peak employed 2,500 people and occupied 116 buildings covering 306 acres. The facility is now called the Mound Business Park and is managed by the Mound Development Corporation.
You can learn more about this interesting bit of Riverway history by visiting Carillon Park. The exhibits from the former Mound Cold War Discovery Center in Miamisburg were moved there after its closure in August 2025. Carillon Park’s Mound Cold War Discovery Center is open now!