MINOT, N.D. — For a very long time this state was derided as an empty expanse of windswept nothingness where snow stormed in and residents stormed out in predictable abundance. Then, as the rest of the country struggled the last few years, North Dakota started winning consistent praise as an oasis of economic prosperity. The snow kept coming, but suddenly so did new residents.

Among them was Lisa Tankersley, whose husband was one of the thousands to land a well-paying job in the oil fields that are helping to drive the economic boom. She arrived at her new home here last Monday afternoon, weary from the two-day drive from East Texas. Fifteen minutes later, not having unloaded a single box, she was ordered by a police officer to evacuate: floodwaters were on the way.

“I was freaking out,” said Ms. Tankersley, who immediately threatened to drive back to Texas but consented to stay indefinitely at the apartment of friends who had also migrated north. “Here I am, hundreds of miles from home, with my two children and all my worldly belongings, and I have no place to live.”

In many ways this has been a year of triumph for North Dakota, home to the nation’s lowest unemployment rate and fastest growing economy. But with historic flooding from one side of the state to the other, this is also the year when North Dakota reminded its residents that even in good times the state is — in the words of Andy Peterson, head of the state Chamber of Commerce — “not for the faint of heart.”