The Fort Berthold Indian Reservation is a U.S. Indian reservation in western North Dakota that is home for the federally recognized Mandan, Hidatsa, and Arikara Nation, also known as the Three Affiliated Tribes. Created in 1870, the reservation is a small part of the lands originally reserved to the tribes by the Fort Laramie Treaty of 1851, which allocated nearly 12 million acres (49,000 km²) in North Dakota, South Dakota, Montana and Wyoming.
Created in 1870 by the U.S. government, the reservation is located on the Missouri River in (in descending order of reservation land) McLean, Mountrail, Dunn, McKenzie, Mercer and Ward counties. The reservation consists of 988,000 acres (4,000 km²), of which 457,837 acres (1,853 km²) are owned by Native Americans, either as individual allotments or communally by the tribe. Allotments were assigned in the late nineteenth and early twentieth century when the US government was trying to have Native Americans adopt European-American land use patterns. The tribe retained some communal holdings and has resisted continued individual allotments since its reorganization in the 1930s. The McLean National Wildlife Refuge lies within its boundaries.
The reservation was named after a United States Army fort located on the northern bank of the Missouri River some twenty miles downstream from the mouth of the Little Missouri River.[1]
In 1951, the US government took reservation land for use to support the construction of Garrison Dam. It flooded approximately a quarter of the reservation land to create Lake Sakakawea. Because of the lake-associated flooding, the seat of reservation offices had to be moved to New Town.
The population of the reservation was 3776, with a total enrollment of 8400 registered tribe members. Unemployment was at 42%. The 2000 census reported a reservation population of 5,915 persons living on a land area of 1,318.895 sq mi (3,415.923 km²). The creation of Lake Sakakawea increased the proportion of water area on the reservation; it totals 263.778 sq mi (683.182 km²) or one-sixth of the reservation's surface area.
The largest communities of the reservation are the cities of New Town and Parshall. The tribe operates a casino built in 1993 in New Town. The Four Bears Bridge, which opened in 2005, provides access across the Missouri River.