Following is a complete list of the approximately 340 dams owned by the United States Bureau of Reclamation as of 2008. The Bureau was established in July 1902 as the "United States Reclamation Service" and was renamed in 1923. The agency has operated in the 17 western states of the continental U.S., divided into five administrative regions. Within the United States Department of the Interior, it oversees water resource management, specifically the oversight and/or operation of numerous diversion, delivery, and storage projects it built throughout the western United States for irrigation, flood control, water supply, and attendant hydroelectric power generation.