refused to sign it until 1944. Even then Arizona continued to dispute its water allotments until a 1963 Supreme Court decision settled the issue. The court has had to adjust the agreement several times since, most recently in 2000. As recently as 2008 Arizona Senator John McCain called for a renegotiation of the plan. In 1935, when Arizona Governor Benjamin Baker Moeur sent 6 members of the Arizona National Guard to observe the dam's construction, they reported back that there was construction activity on the Arizona side of the river. Arizona Attorney General Arthur La Prade concluded that the Metropolitan Water District had no right to build on Arizona's territory, which prompted Governor Moeur to send a larger National Guard force to halt construction. The troops were recalled when Secretary of the Interior Harold L. Ickes halted construction until the issue had been settled. The Department of the Interior took Arizona to court over the issue hoping to end the state's interference. To the Department of the Interior's surprise, the Supreme Court sided with Arizona and dismissed the injunction. The court concluded that the dam had never been directly approved by Congress and that California was not entitled to build on Arizona's land without Arizona's consent. Arizona eventually agreed to allow the dam in exchange for approval of the Gila River irrigation project. Gallery See also List of dams and reservoirs in California List of largest reservoirs of California List of power stations in California List of tallest dams in the United States List of United States Bureau of Reclamation dams References External links USBR – Parker-Davis Project USGS – Real-time water data for Colorado River below Parker Dam Profile on desertusa.com Dams in California Dams in Arizona Dams of the Lower Colorado River Valley Hydroelectric power plants in California Hydroelectric power plants in Arizona Buildings and structures in La Paz County, Arizona Landmarks in California Landmarks in Arizona Buildings and structures in San Bernardino County, California Lake Havasu United States Bureau of Reclamation dams Historic American Engineering Record in Arizona Historic American Engineering Record in California Dams completed in 1938 Energy infrastructure completed in 1938 Arch-gravity dams 1938 establishments in Arizona Dams on the Colorado River 1938 establishments in California