Herbert Wilson came to North Dakota's Fort Berthold Indian Reservation in 1954, to a tiny town called Elbowoods, tucked above the Missouri River in a bucolic patchwork of riverside willows, cottonwoods and fields. A Vermont-bred 33-year-old, fresh from Harvard and a tour as a WWII bombardier, Wilson was the new, sole doctor for the reservation's three tribes, which had spent the years since white colonization the same way they had spent the preceding millennia -- raising corn, beans and squash in the Missouri's fertile floodplain.

"Very few people were overweight," recalls Dr. Wilson. "There was no welfare, no commodity food, and did I mention there was no diabetes?"

But even as Wilson and his wife unloaded their four small children and cat from their 1946 Hudson sedan, the disease that has become the hallmark of the Native American health crisis was on its way. The recently constructed Garrison Dam would soon flood Elbowoods and seven other Native communities along a 30-mile stretch of the Missouri, ushering the resident Mandan, Hidatsa and Arikara people to high, barren ground and the end of their farming traditions. The move triggered unemployment, poverty, and a five-decade descent into obesity, hypertension, and diabetes, conditions that are linked to each other and to nutrition. Ironically, the flood would drown the only hospital the reservation has ever had.

Dams aren't the only way to destroy indigenous lifestyles. The health history of the Fort Berthold people differs from that of other tribes only in the details. After white settlement, Native Americans from California to New York were cut off from their land and their way of life. Like the Fort Berthold tribes, they became more sedentary, relied more on cheap food -- often from the federal government -- and received worse health care than any other group of people in the country. Nowadays, Indians suffer more diabetes than any other racial group. They are 2.2 times more likely to get it than non-Hispanic whites and three times more likely to die of it than non-Indians. A new $20-million clinic will open on Fort Berthold later this year, but it will take a lot more than that to turn the tide of the health crisis inundating this and other reservations.

Says one local,  "You see all these young people, and they're all sick, and you wonder, 'God, what's gonna happen to them in 10 more years?' "

Relations between the U.S. government and the people of Fort Berthold began harmoniously. The Mandan lived in villages with the Hidatsa, in lodges walled thick against raiders.

"We grew large gardens," says Marilyn Hudson, great-great granddaughter of Mandan chief Cherry Necklace and the tribes' ad hoc historian. "We had a very organized society, which was similar to the white European societies. There were systems of law and order, food distribution. ... I think it made the people here more compatible with Europeans because they were farmers."

When the Indian Wars began in the second half of the 1800s, the Mandan and Hidatsa -- along with the Arikara, with whom they allied in 1862 -- signed on as government scouts. In 1870, the land that the Three Affiliated Tribes had occupied for centuries was designated as the Fort Berthold Indian Reservation.

The people ran small farms, sent their children to school, attended church and took pride in serving in the United States armed forces. Women and children cultivated beans, potatoes, carrots and beets, storing them for winter, and harvested wild juneberries, chokecherries, buffalo berries and prairie turnips, the same fare they shared with Lewis and Clark in the long winter of 1805. The men used horses to sow corn and cut hay; families also raised cattle, pigs and chickens. "Almost everything grown in the garden was consumed by us and our livestock," remembers Hudson, 74. "The only thing we bought from the store was sugar, coffee, salt."

And then, in the mid-1940s, the U.S. government decided it needed a dam.

"Of all the variable things in creation," wrote the editor of the Sioux City Register in 1863, "the most uncertain are the actions of juries, the state of a woman's mind, and the condition of the Missouri River."

In 1943, the restive Missouri had jumped its banks three times, inundating Iowa and Nebraska and angering precisely the wrong person -- Col. Lewis Pick, the short-fused regional director of the Army Corps of Engineers. "As the floodwaters rose in the streets outside his offices, Pick jumped up on a desk and bellowed at his subordinates: 'I want to control the Missouri!' " wrote Paul VanDevelder in Coyote Warrior, a history of the Garrison Dam and its effect on the tribes.

President Franklin Roosevelt ordered Pick to hammer out a plan with the Bureau of Reclamation. It called for a series of dams on the Upper Missouri, with, at its center, a 200-mile-long reservoir. The new Lake Sakakawea would flood 436 of Fort Berthold's 531 homes, as well as every square foot of the enviable farmland tilled by the tribes.

The tribes fought back. When Pick, who was now a general, appeared at an Elbowoods hearing in 1946, Thomas Spotted Wolf, a rancher with a third-grade education and a full-feathered war bonnet, stood up and stuck his finger into Pick's face.

"You have come to destroy us!" he shouted, according to his grandson, Jim Bear. "If you look around in our town, we build schools, churches. ... We're becoming civilized! We're becoming acculturated! Isn't that what you white people wanted us to do? So we're doing that! And now you'll flood our homeland?"

But the government was determined to tame the Missouri, no matter the cost. VanDevelder reports that of the 800 square miles of rich bottomland lost to dams above Yankton, S.D., about three-quarters was Indian land.

In the end, the tribes accepted the U.S. government's offer of $5 million in exchange for their land. At the signing ceremony on May 20, 1948, in Washington, D.C., the bureaucrats were straight-faced. The suit-clad tribal chairman, George Gillette, stood just to the right of Interior Secretary Julius Krug, sobbing into his hand.