The seven urban and suburban counties in the Twin Cities metro area have hit the 3 million mark for the first time, and as a group are growing six times faster than the rest of the state.

The Metropolitan Council seized on both facts Wednesday in its quest for a big boost in Twin Cities transportation funding from the Legislature.

"Are we equipped to compete into the future?" asked Council Chairman Adam Duininck. "We're beating a lot of peer regions in the Midwest but struggling to keep up with a Dallas, or Denver or Seattle."

State Demographer Susan Brower noted, however, that "most other metros in the state are showing moderate to strong growth as well."

Fargo-Moorhead grew by 12 percent between 2010 and 2015, she said, and Clay County, Minn., was an important contributor to that metro area's growth. Between 2014 and 2015 the St. Cloud metro area grew by nearly 1 percent, a one-year pace that she said was on par with the rate of growth of the Twin Cities metro area.

The seven inner metro Twin Cities counties have grown by 162,000 people, or 5.7 percent, in the half-decade since the last federal census in 2010, compared with growth in outstate Minnesota of 0.9 percent during that period.

Both Brower and the Met Council's analysts noted that the greatest boost to the Twin Cities metro area's population is coming not from transfers from other states but from the maternity ward. About two-thirds of the area's growth has come from births exceeding deaths, and the rest from international arrivals.

Both the babies and the new arrivals, in fact, are having to compensate for a net outflow of Twin Citians.

"More people are moving out of the Twin Cities metro to other places in the U.S., whether within Minnesota or outside of it, than are moving to the Twin Cities from other places in the U.S.," Brower said.

That, she added, was "something we've talked about before at the state level. Most people aren't aware that the same pattern holds true for the Twin Cities metro."

Net outflow from Cities

The latest data come from a new set of Census Bureau estimates for 2015, to be publicly released Thursday after having been shared privately with demographers and journalists this week.

The question of how seriously to take the net outflow of Twin Citians to other parts of the state and nation is tricky, demographers say. It might prove temporary if young adults moving out of state to college end up returning.

"We've looked at this in detail at the state level," Brower said, "and found that most of the losses are among young people, those in their late teens to early 20s, and a large share of those young people are moving out of state to go to school. The pattern may look different at the metro level, but young adults are much more likely to migrate, compared with older adults."

But Duininck called it a source of concern.

"When I meet with the business community, they talk about 'attract and retain,' with emphasis on the 'retain,' " he said. "It's on the minds of Fortune 500 companies, not just to attract from outside the region but to keep people here who grew up here, including college students."

3 million and counting

Nevertheless, Met Council spokeswoman Kate Brickman noted the outsized role for the metro area in the state's growth.

"The Twin Cities region has 55 percent of the state's population but accounted for 88 percent of the state's net population growth since 2010," she said.

On the other hand, public investment is needed across the state if Minnesota is to thrive from border to border, said Bradley Peterson, a lobbyist for the Coalition of Greater Minnesota Cities.

"In fact, Greater Minnesota communities often don't have the economies of scale that exist in the metro, so they need extra assistance from the state," he said.

The jump past 3 million involves only the seven metro counties overseen by the Met Council — not the Minneapolis-St. Paul-Bloomington Metropolitan Statistical Area.

The latter is a 16-county behemoth that stretches into Wisconsin and ranks 16th nationally; that entity is now over 3.5 million.

Among the findings in the latest Census Bureau data:

• Clay County, which has Moorhead as its county seat, has shot past the state's traditional growth leaders — the suburban enclaves of Scott and Carver counties — to become the fastest-growing Minnesota county in percentage terms.

• The Fargo-Moorhead area itself is the fastest-growing metro area in the Midwest and Northeast states, stretching from Kansas to Maine.

• Metro counties in the Twin Cities area are bunched together in growth rates, a far cry from the days when Scott and Carver experienced hypergrowth while Ramsey County sputtered or declined. Since 2010, the growth of metro counties ranges from Scott and Carver's 8 to 9 percent at the top end to Anoka and Dakota's 4 percent at the bottom.

David Peterson • 651-925-5039