North Dakota was the nation's fastest-growing state in the past year.
U.S. Census Bureau data show that North Dakota's population grew 2.2 percent to 699,628 in the year ending July 1, as the oil boom drew workers to the Bakken fields in the western part of the state.
"We had rural population declining in western North Dakota for decades," said Dean Bangsund, an economist at North Dakota State University in Fargo who has studied the effects of the oil boom. "Now we are looking at growth curves that are just short of astonishing."
By contrast, Minnesota's population in the year ending July 1 grew 0.6 percent, according to the Census Bureau.
North Dakota this year became the No. 2 oil-producing state behind Texas as drillers tapped into shale oil deposits and began pumping record amounts of crude. In October, the oil output was 747,239 barrels, nearly six times the output of five years ago.
Rod Backman, chairman of the North Dakota Census Committee, a group of mostly state officials who advise the government, said the census estimates don't include at least 24,000 workers who live in temporary camps set up mainly for migrant oil workers.
He and others see no sign of the population trends changing in the years ahead.
"At some point the drilling is not going to be as fast-paced as it is now," said Backman, CEO of Covenant Consulting Group, an accounting and consulting firm in Bismarck. "But when you start factoring in the permanent jobs, the expectation is that we are going to continue to see job growth and population growth."