While acknowledging the strong growth presents challenges to the state's education and transportation systems, as well as social services and the environment, a state official cheered the designation.

"It means our economy is strong," said Robert Spendlove, manager of the state's Demographic and Economic Analysis section. "There are people moving into Utah. Utah is seen as a good place to live and good place to raise families."

The U.S. Census Bureau said Utah gained almost 37,000 residents from July 2003 to July 2004, bringing the population to 2.39 million. Nevada's growth rate again led the nation. So did the Western region. Arizona was ranked second, Idaho fourth and New Mexico 10th. Five coastal states, from Delaware to Texas, rounded out the top 10.

The Census Bureau now puts the U.S. population at 293.7 million.

The federal government's figures for Utah are low, according to state-generated estimates, which show Utah gained 55,612 residents for a total population of 2.47 million. Of the gain, natural growth (births minus deaths) accounted for 37,245, and migration (those arriving from elsewhere minus those leaving the state) was 18,367, said Spendlove.

"It's baby heaven time," said Pamela Perlich, a senior analyst with the University of Utah's Bureau of Economic and Business Research.

She said the masses of children born in the early 1980s - the last time births peaked - are now having children. In fact, in the past several years, Utah has continued to break its birthing records. From 2003 to 2004, 50,527 babies were born, a new high.

Perlich said international immigrants also are helping fuel this latest baby boom. Most travel here and then have children.

"Our immigrant population[s] that are coming, some of them have even higher fertility rates" than native Utahns' legendary performance, said Perlich.

Figures from 2002 show white women have an average of 2.45 births while Latinas' fertility rate is 3.53. The minority population made up 40 percent of Utah's population growth from 2000 to 2003, Perlich said.

Many migrants are moving to Utah because of the state's relatively strong economy, Spendlove added. The state forecasts a 2.5 percent job growth for 2004, compared with the nation's 1 percent growth rate, he said.

Death is a factor, too. Utah's life expectancy at 78.6 years, is third highest in the nation.

State figures show Washington County in southern Utah was the fastest-growing county in the state this past year, jumping 6.9 percent to 117,300.

Washington County Commissioner Alan Gardner didn't need any ranking to tell him his county is bustling. It's been growing at a breakneck pace for at least the past five years.

"We've just got subdivisions going in like crazy. As soon as a subdivision is platted, it's sold out. We just can't build them fast enough."

The growth has enabled the county to keep property taxes low, but it brings challenges. The county has hired six new police officers and two more assessors. Traffic is snarled and beltways are on the way. Home prices are skyrocketing.

"I'm amazed at the growth and wonder who's moving in or how they're able to afford the homes being built here," Gardner said.

Carbon County is at the other extreme. It lost 173 residents over the past year and 1,000 since 2000. Delynn Fielding, the county's economic development director, noted a coal mine closed three years ago and many jobs at other coal mines have been lost to machines.

But he remains optimistic: Other industries looking for an "educated blue-collar type of work force" have made inquires. And the county is hoping the College of Eastern Utah's Prehistoric Museum will continue to draw tourists and academics to Price.

The population estimates are "a little discouraging," Fielding said. "Housing is less expensive, if that's any consolation."

hmay@sltrib.com