Fort Berthold Reservation

The Fort Berthold Reservation in western North Dakota is home to the MHA Nation, the Mandan, Hidatsa and Arikara peoples, also known as the Three Affiliated Tribes. These were farming peoples of the upper Missouri River, and it was in their earth-lodge villages that Lewis and Clark spent the winter of 1804–05 and met Sakakawea. Their treaty lands once covered about 12 million acres, and the reservation created in 1870 was cut down several times. The tribal seat is New Town.

The great wound of the 20th century was Garrison Dam, built from 1947 to 1953, whose reservoir, Lake Sakakawea, flooded 152,360 acres of the reservation's most fertile river bottomland, forced about 1,700 people from their homes and drowned towns and graves. Today the lake splits the reservation into pieces. Since the 2000s the reservation has sat atop the Bakken oil boom, and oil and gas now provide roughly 90 percent of the Nation's revenue. Ownership of the minerals under the Missouri riverbed has flipped back and forth in federal opinions, most recently in favor of North Dakota in 2026.

• Lake Sakakawea
  The Garrison Dam reservoir on the Missouri River in North Dakota borders
• North Dakota
  The Peace Garden State, northern plains and badlands located in
• The Missouri River
  The longest river in North America related