Provo, one of three Utah cities that in 2003 had a population of more than 100,000, has dropped from the U.S. Census Bureau's 2004 list of "large cities."

That means Salt Lake City and West Valley City remain Utah's only two cities with populations greater than 100,000, according to new census population estimates.

Provo officials, however, believe the census data are wrong — and they plan on letting census officials know that they beg to differ.

Meanwhile, smaller Utah cities — many in southwestern Salt Lake County or northwestern Utah County — continued to drive much of the population growth along the Wasatch Front from July 1, 2003, to July 1, 2004.

Southwestern Utah is also seeing strong growth, with an influx of 3,256 individuals into St. George and 1,003 into the nearby city of Washington.

With a July 1, 2004, estimated population of 99,624, Provo was the nation's only large city that fell below 100,000 last year, census spokesman Robert Bernstein said.

However, Provo officials are considering a challenge to the Census Bureau's population estimate, saying they project a population of 115,000 for July 1, 2005.

"I don't know if somebody hit the wrong key or needs their glasses wiped," Provo Mayor Lewis Billings said of the census estimate. "We have successfully challenged the census numbers previously, and it looks like we'll be doing that again. We feel comfortable we'll fall between 110,000 and 115,000."

Robert Spendlove, manager of demographic and economic analysis for the Governor's Office of Planning and Budget, said that until the 2010 U.S. Census, it won't be known exactly how many people live in any of Utah's cities, including Provo.

"Whether or not Provo . . . is actually dropping in population right now, no one knows for sure," he said. "You could say the population of Provo, without a doubt, is growing at a much slower rate than surrounding areas."

Spendlove said, for the most part, the census trends aren't a surprise.

"What we're seeing is that the older, more established cities are experiencing slower population growth," he said. "Areas that 10 to 15 years ago were not even bedroom communities . . . are becoming new bedroom communities or growth centers."

Salt Lake City, with a 2004 estimated population of 178,605, saw a slight population decline. West Valley City grew by slightly more than 1 percent to an estimated 112,678.

Meanwhile, Herriman in southwestern Salt Lake County, which incorporated in 1999, is booming. Its population of about 1,500, according to the 2000 estimates base, has grown by more than 400 percent to an estimated 7,826 — an average growth rate of 50 percent per year.