The Fort Laramie Treaty of 1851 recognized nearly 12 million acres belonging to the Three Affiliated Tribes - lands spanning North Dakota, South Dakota, Montana, Nebraska, and Wyoming. By 1870, when the U.S. government formally created the Fort Berthold Reservation, that territory had already shrunk dramatically. Executive orders in 1880 and 1886 reduced holdings further. The Dawes Act forced the division of communal lands into individual allotments, breaking apart a way of life that had thrived on collective stewardship. The reservation today encompasses 988,000 acres straddling the Missouri River across six North Dakota counties, but only 457,837 acres remain in Native ownership. The rest passed to non-Native hands through the allotment system designed to, in the government's words, encourage "subsistence farming in the European-American style."

For centuries, the Mandan, Hidatsa, and Arikara peoples lived in earth lodge villages along the Missouri River, their permanent settlements centered on farming, trading, and the river's abundant resources. Like-a-Fishhook Village served as the last great concentration of these three nations before the reservation era. Then came Garrison Dam. Constructed between 1947 and 1953, the dam created Lake Sakakawea - and drowned the heart of the reservation. The flooding destroyed the bottomlands where families had farmed and ranched for generations. It submerged towns, severed communities, and scattered a people whose identity was tied to the river. Today, water covers 263 square miles of the reservation - one-sixth of its total surface area. The lake that destroyed so much now defines the reservation's geography.

The original Four Bears Bridge opened in 1955, a lifeline connecting reservation communities separated by the new lake. For fifty years it served as the primary route across Lake Sakakawea, named after the great Mandan chief Four Bears who led his people through the devastating smallpox epidemic of 1837. The replacement bridge, opened in 2005, carries traffic between New Town on the north shore and communities to the south. New Town serves as tribal headquarters, the 18th largest city in North Dakota, home to the tribal government offices and the 4 Bears Casino and Lodge built in 1993. Other communities - Mandaree, Parshall, Twin Buttes, White Shield - dot the reservation's vast expanse, connected by roads that wind around the lake's intricate shoreline.

Geology offered the Three Affiliated Tribes an unexpected turn of fortune. The Bakken shale formation, a layer of oil-bearing rock extending beneath western North Dakota, underlies significant portions of the reservation. When hydraulic fracturing and directional drilling technologies made Bakken extraction economically viable around 2000, the reservation found itself positioned atop one of America's largest oil fields. The boom brought wealth, jobs, and complications. Oil revenues transformed tribal finances, but rapid development strained infrastructure and communities. The contrast with the flooding that destroyed tribal lands half a century earlier carries bitter irony - the same federal government that took their best farmland now leases mineral rights on what remained.

The Mandan, Hidatsa, and Arikara were three distinct peoples who came together through circumstance and survival. The Mandan and Hidatsa were Missouri River village dwellers when the Arikara, pushed north by conflict and disease, joined them in the nineteenth century. Smallpox epidemics had devastated all three nations, forcing consolidation for survival. That history of adaptation continues. The tribe has resisted further allotment of communal lands since reorganizing in the 1930s. New initiatives include a massive greenhouse operation returning to agricultural roots. Unemployment remains high at 42 percent, and many tribal members have moved to cities seeking opportunity. But the Fort Berthold Reservation endures, its 988,000 acres a fragment of what was promised at Fort Laramie, yet still homeland to a people who have survived epidemics, forced relocations, flooded valleys, and the boom-and-bust cycles of American extraction.