Utah's fast-paced population growth is projected to continue through 2030 at a growth rate ranked fifth in the nation, according to population projections for 2000 to 2030 released today by the U.S. Census Bureau.

The projections also show the Beehive State keeping its ranking as the youngest state, even with a rapidly growing senior population.

Utah's population is expected to approach 3.5 million by 2030 — a growth rate of 56 percent over three decades, according to the projections.

Utah is part of the nation's fastest-growing region, the Mountain West, expected to grow by 65 percent from 2000 to 2030.

The United States, meanwhile, is expected to grow by 29 percent to nearly 82.2 million people.

Utah's neighbors, Nevada and Arizona, are projected to be the two fastest-growing states — each more than doubling in population. Idaho, projected to grow by 52 percent to nearly 2 million people, ranks sixth in growth nationally.

While Utah is projected to move up in the state size rankings to 31, Nevada, which ranked just behind Utah in 2000, is projected to surpass Utah in size, with a 2030 projected population of 4.3 million — making it the 28th most-populous state. Arizona's projected population of 10.7 million would make it the 10th most-populous.

Utah's official population projections show even faster growth than the census, with 4.1 million residents by 2030, said Pam Perlich, senior research economist at the University of Utah's Bureau of Economic and Business Research.

"I think they've underprojected us," Perlich said. "We should go up a little higher in these rankings and stay a little closer to Nevada."

Robert Spendlove, manager of demographic and economic analysis for the Governor's Office of Planning and Budget, said even though the census projections do differ slightly from the state projections because of different methodology, they do seem to show "pretty accurate ongoing trends. . . . When you're 25 years away, the range of possible projections is pretty big.

"Utah will be one of the fast-growing states," he said. "We have strong economic growth, strong natural increase, a young population and larger families than the national average."

The census projections show a rapidly aging population nationwide. The projected 71.5 million seniors in 2030 would comprise 20 percent of the nation's population.

As the oldest baby boomers become senior citizens in 2011, the 65-and-older population is projected to grow faster than the total population in every state.

Utah is projected to gain 270,331 people age 65 and older by 2030, more than double the 2000 senior population. The projections show a 2030 senior population of 460,553, or 13.2 percent of the state's population.