The activities in this study consists of a compilation of data for an inventory of dams; a survey of each state and federal agency's capabilities, practices and regulations in regard to the design, construction, operation and maintenance of dams; development of guidelines for the safety inspection and evaluation of dams; and recommendations of a comprehensive national program for the inspection and regulation of dams. The inventory included in the report consists of data on 49,329 dams which are 25 feet or more in height or have a maximum impounding capacity of 50 acre-feet or more. Inventory data consists of the name of the dam; the river or stream on which the dam is located; the type of dam; year completed; purpose of the dam; height and maximum storage capacity; and the name, population and distance from the dam to the nearest downstream city, town or village; the downstream hazard potential; owner of the dam; and the Congressional district in which the dam is located. This report presents the first Federal study of the problems of the safety of dams on a nationwide scale. It reveals that approximately 20,000 of the 49,329 dams are so located that failure or misoperation of the discharge facilities could result in loss of human life and appreciable or greater property damage. It was also found that existing dam safety programs in most states and in some Federal agencies are either non-existence or inadequate.