Sl * FOREWORD This monograph recounts the activities of the United States Air Force, through Task Group 7.4, in the 1957-1958 muclear test series, Operation HARDTACK, an operation conducted in the Eniwetok Proving Ground, point. All phases of the series ere treated from an over-view standFor detailed information on various aspects of the operation, the reader is invited to examine other related documents, chief among these being the Commander's Final Report and Task Group 7.4 Operation Plan 1-58, The cited documents are retained in the files of the Hia- torian, 4950th Test Group (Nuclear), Kirtland Air Force Base, New Mexivo, Master Sergeant William A. Evans wrote all portions of this monograph. Airman Second Class Joaquim S. Geraldo Jr. performed the as- sociated clerical tasks, The author is endebted to the Staff of Task Group 7.4 for guidance and cooperation in the preparation of the document, This monograph fs subject to revision, Thus, additional infor- mation or suggested corrections will be welcomed. AFWL/HQ _= AFWL/ HQ