explosives fabrication and assembly were performed at Inyokern and Burlington. nators were fabricated at Rock Island and at Picatinny Arsenal. Deto- Mechanical components were fabricated at Kansas City. LASL performed research, development, production, and product acceptance of nuclear and high explosive components, and carried heavy test responsibilities. Sandia performed research, development, testing, production, and product acceptance of inert components, performed stockpile surveillance, and a heavy program of liaison and training work withthe Military. Staff Supervisory and Operating Programs Reflecting the concentration of mission operations in Los Alamos and the key importance of stabilizing and building the Los Alamosactivity, a major proportion of SFOO headquarters staff attention was devoted to Los Alamos throughout the period. Supervision and contract administration, outside of Los Alamos, was conducted almost ex- clusively by SFOO Field Offices. The Office of Production Coordination, organized in 1948, was the first staff supervisory program to be truly operations-wide. Two operating functions, operations-wide in nature, were also assigned to this office: Control of fissionable materials, and custody of stockpiled weapons. Near the end of the period, a reorganization was effected to provide more resources for operations-wide action while simultaneously establishing concentrated responsibility for Los Alamos community operations. Status of Mission Achievement, July 1950 In many respects the period was one of building—programs, as well as supporting plant and organization—with the full capacity of the new resourcesto be felt most strongly in the subsequent three years. Nonetheless, the steadily-increasing national requirements for training and War Reserve weapons were met. Of peculiar importance in supporting mission achievement was the building and development of Los Alamos community to a point where LASL could obtain and retain the personnel it required. Major progress was made toward giving Los Alamosresidents self-government and helping them to achieve a considerable measure of selfsupport. The Government's 1949 contribution of $4, 403, 000 to community operations was reduced to $1, 883, 000 for 1950. A feature of the period was the conduct, as a ship-based operation at Eniwetok Atoll, of the first full-scale nuclear field test series under the AEC. Theories proved in this series were being reflected in stockpile modifications by mid-1950 and were pointing the way to development of other more flexible weapons. The results of the comparatively small amount of knowledge obtained from this series were so immediate that LASL recommended constructing a permanent proving grounds at Eniwetok. The general and extensive expansion of production—utilizing AEC, military, and private industrial facilities and resources-—permitted a strategically important dispersal. It resulted in relieving LASL of some production so that it could concentrate on development. It resulted also in changing weapons production from a custom-built, laboratory operation to an industrial operation. Activation of Sandia Laboratory not only contributed considerably to 1947-1950 results but was a major factor in providing a broad and flexible basis for meeting the very heavy requirements of “aOa years. .