This paper provides a view of the pattern of reported Unidentified Aerospace Phenomena (UAP) in the United States associated with the military atomic weapons complex between 1945 and 1975. A set of 590 comprehensively documented UAP reports from this period were collected from select sources, including Project Blue Book. These were analyzed graphically for spatial and temporal differences between the number of incidents reported at sites within the atomic warfare complex, and control sites. Initial study site classes were: 1) radioactive materials production plants; 2) atomic weapons assembly facilities, and 3) atomic weapons stockpile sites. Control sites classes were 1) civilian population centers and 2) high-security, non-atomic weapons military bases. Elevated UAP activity was found at all three atomic site classes and was most noticeable in the earliest facility in each class. UAP activity began during the construction phase for some sites and escalated when the site became operational. Elevated activity at study sites occurred in a “window” between 1948-1951, continued through the national spike in UAP reporting in 1952, then dramatically decreased, never to repeat the “window” levels during the remainder of the study period. The second phase of the study compared additional atomic weapons deployment sites vs: 4) additional non-atomic military sites, and 5) major American rocket/missile and aerospace test and development facilities. Moderately elevated UAP activity was associated with bases where atomic weapons were operationally deployed (Air Force and Navy). Distinctive patterns of UAP activity were noted in conjunction with the deployment of Inter-Continental Ballistic Missiles (ICBM), and other individual and distinctive patterns of UAP incident reports were noted for different types of atomic weapons complex sites over the full period of this study.