text: Under the 1934 Indian Reorganization Act, which encouraged tribes to restore their governments, the Mandan officially merged with the Hidatsa and the Arikara. They drafted a constitution to elect representative government and formed the federally recognized Three Affiliated Tribes, known as the Mandan, Hidatsa and Arikara Nation.
  In 1951, the U.S. Army Corps of Engineers began construction of Garrison Dam on the Missouri River. Developed for flood control and irrigation, this dam created Lake Sakakawea. It flooded portions of the Fort Berthold Reservation, including the villages of Fort Berthold and Elbowoods, as well as a number of other villages. The former residents of these villages were moved and New Town was constructed for them.
  While New Town was constructed for the displaced tribal members, much damage was done to the social and economic foundations of the reservation by the loss of flooded areas. The flooding claimed approximately one quarter of the reservation's land. This land contained some of the most fertile agricultural areas upon which their economy had been developed. The Mandan did not have other land that was as fertile or viable for agriculture. In addition, the flooding claimed the sites of historic villages and archaeological sites with sacred meaning for the peoples.
  Culture