Among the project's dozens of sites were: Hanford Site in Washington state, which had the first industrial-scale nuclear reactors; Oak Ridge, Tennessee, which was primarily concerned with uranium enrichment; and Los Alamos, in New Mexico, which was the scientific hub for research on bomb development and design.
Blandt projektets dusinvis af lokaliteter kan nævnes: Hanford Site i staten Washington, som havde de første reaktorer i stor skala; Oak Ridge, Tennessee, der primært arbejdede med berigelse; og Los Alamos, i New Mexico, der var det videnskabelige omdrejningspunkt for forskning i atombombe konstruktion.