For Kasidy and Brittany Olsen, starting a family was a natural extension of their LDS faith.

"We wanted to have kids so we could enjoy it," Brittany Olsen says. "And our religious background is LDS. A big part of that is to have a family."

The Bountiful couple now has a 7-week-old daughter, and like nearly one in three Utah households, are married with children, according to a survey released Tuesday by the U.S. Census Bureau.

Utah has the highest rate of married couples with children in the nation, where an estimated 22 percent of households fall into that category, according to the 2006 American Community Survey.

And, in a nation where one in five households speaks a language other than English at home, Utah is also seeing an influx of immigrants. However, the state's growth is dominated by a new baby boom, says Pamela Perlich, senior research economist at the University of Utah.

"We're in record, record births," Perlich says. "A lot of the immigrants who came in the 1990s are having kids now, and the baby boom that peaked in the 1980s, those (young adults) are having their own kids."

The state's unique culture, rooted in the theology of The Church of Jesus Christ of Latter-day Saints, encourages Utahns to marry younger than in other states, says Nicholas Wolfinger, associate professor of family and consumer studies at the U.

"A fairly normative pattern of relationship formation is to go on a mission, go home and get married," Wolfinger says.

Nationally, the percentage of married-with-children households declined from 23.5 percent to 21.6 percent from 2000 to 2006, according to the ACS. Utah also saw a slight decline in that percentage, which was at 35 percent in 2000 and 32 percent in 2006.

Even with a slight increase in the number of unmarried couples and in the number of single mothers, the drop is more likely due to the aging baby boomer generation than anything else, says Juliette Tennert, the state's top demographer.

"Their kids are getting older and moving out," she says. "They're getting to the point of starting families of their own."

Meanwhile, the state is continuing to see an influx of people from other states and nations.

In 2006, more than 24,000 people reported living in another nation a year ago, and some 101,000 people reported they had lived in a different state.

"If the data of the past is holding, the bulk are coming from California, and many are foreign-born," Perlich says.

Nationally, 8 million more people spoke a foreign language at home in 2006 than in 2000, according to the ACS.