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New construction is pictured in Broomfield on Wednesday, June 9, 2021. Photo by Andy Colwell, special to The Colorado Sun

Colorado’s population grew at nearly twice the rate of the rest of the nation between 2010 and 2020, putting it among the fastest-growing states, the U.S. Census Bureau reported Thursday.

While the nation’s population grew only 7.4% over that period, Colorado saw nearly 15% growth. But the growth was unevenly distributed, with urban centers continuing to draw more residents and rural counties, especially those in the southeast corner of the state, seeing the biggest declines in population. 

As it has for the past decade, population is falling on the Eastern Plains and in the San Luis Valley and growing along the urban Front Range, especially in Adams, Douglas, Larimer and Weld counties. 

“From a historical perspective, it is a little unusual,” State Demographer Elizabeth Garner said. “Typically we see about anywhere from 85-ish percent of the growth to be along the Front Range, and actually what we’re seeing this decade is closer to 95%” of the growth.

It’s a similar pattern with jobs, largely because of the pre-pandemic growth in demand for food, health and professional technical services, fields that “are associated with people,” she said. “Look where all the people are, and they’re along the Front Range.”

The state’s white population declined while the Hispanic population increased, similar to national trends. 

The data released Thursday is the first detailed population numbers from the 2020 Census. It will be used to redraw the state’s congressional and legislative maps used for the next 10 years. 

But the data also is used to allocate an estimated $13 billion in federal funds each year for a variety of programs in Colorado. Later releases will include more detailed information about housing, income, country of origin and more.

Colorado’s growth mirrors that of other states in the West that grew faster than the national average. It’s a trend that began in the past century. The state’s population more than doubled in the past 40 years, with much of that growth occurring between 1990 and 2000.

Going forward, Garner expects the state’s population growth to slow — as it will be building on a “larger base” — and that the growth rate of people under 18 will start to lag, possibly dropping to zero or becoming negative. 

“We’re going to be aging — our fastest growing age group is 65-plus — so we will continue to see that. We’ve just got a large group of baby boomers aging into that 65-plus and then fewer and fewer babies,” she said. 

MORE: It’s official: Colorado will get an eighth congressional seat in 2022

Experts cautioned that the 2020 numbers aren’t perfect. A number of advocacy groups nationwide and in Colorado are concerned that Latinos and other people of color were undercounted. The coronavirus began to spread as the census rolled out in March 2020. Some people didn’t respond, others didn’t include information about race and ethnicity.

The data released Thursday is also in raw form — an effort by the Census Bureau to release it as soon as possible — so the state demographer’s office, redistricting staff and interest groups alike are still processing and analyzing the data. 

Garner could not immediately comment on the quality of the census data, but would expect the “biggest issues” to be in the smallest places. 

The Census Bureau used a new statistical method this year to anonymize data in small communities, part of their policy to protect the privacy of people who participate in the survey, which will make population counts and other data on hyperlocal levels, including counts for prisons, college dorms and small rural towns, less accurate. 

“If you’re missing 10 people in Denver, you don’t know it. If you’re missing 10 people in Hinsdale (County), you might know it,” Garner said. 

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Urban counties gained, rural counties lost people

Broomfield, Weld and Douglas counties led the state in population growth between 2010 and 2020, while smaller counties, mostly in the Eastern Plains, posted population declines during that span. Broomfield County led the way in growth over the decade at nearly 33%, followed by Weld County at 30%. 

The population in 31 Colorado counties grew 5% or more over the past decade, while 16 of the state’s 64 counties lost population.

Weld County’s location — close to the foothills and an hour’s drive to major sporting events — could be drawing new residents, as could the affordable price of homes compared to neighboring counties, Commissioner Steve Moreno said. 

Denver and El Paso county have handed the “largest county” title back and forth over the past 10 years, Garner said. Although El Paso is the largest in the state now, with 730,395 people, surpassing Denver County, with 715,522 people, Denver had a greater change in population, increasing by 115,000. El Paso grew by 108,000 people. 

The only small county to post a large percentage of growth was Mineral, with Creede as its only incorporated town, which grew to 865 people from 712, or 21.5%.

There, county officials attributed the population surge to an influx of residents, an undercount in the 2010 census and an aggressive push to increase participation this time around. 

Mineral County Commissioner Jesse Albright also said the recent growth reflected Creede’s identity as a tourism town, its safety and the opening of a “quality school” that was built about five years ago. He estimated the population had grown steadily for 10 years but took off in the past two or three, including during the pandemic. 

“It’s been coming for a while,” said Albright, a builder with kids in the local school. “The community itself is really strong and I think people that have traveled over the years have become a big part of it and decided this would be where they’d like to settle. 

With great broadband, the “work-from-home aspect is huge,” he said. “I know three or four families moved from the Boulder area here.”

The county also has a large number of registered voters who split their time between Mineral County and other states, which could have affected the census counts in 2010 or 2020, he said.

Meanwhile, Kit Carson County saw the greatest population loss over the past decade, which officials largely attribute to the closure in 2016 of a local prison, the privately owned Kit Carson Correctional Center in Burlington. 

“Those prisoners that were in there are no longer there, the prison is completely empty,” Kit Carson County Commissioner Stan Hitchcock said. Some of the prison employees lived in Kansas, but the loss of the prison jobs also affects the economy. “That’s just reality. Those jobs were lost,” he said. 

State Rep. Rod Pelton, a Republican rancher who represents the county, said that parts of the Eastern Plains have been losing residents because “we just can’t seem to really generate economic growth at all.” 

“The labor force is stretched so thin that these companies, to move in, need a labor force and we don’t have enough people to support what we already have,” he said. 

“With a loss of population, of course, we start to lose some representation,” he said. “Right now there’s basically two representatives out here on the Eastern Plains anyway. Rep. Richard Holtorf and I represent 35% to 40% of the state landmass, and so it’s hard to get much less representation than that.” 

In the northwest corner of the state, Rio Blanco County lost 2.1% of its population over the past decade, which Commissioner Gary Moyer blamed on the loss of fossil fuel-based industries that he said have been a primary economic driver and paid 80% of county taxes in past years. 

“We’re watching our budgets crash because of the loss of the fossil fuel industry so this doesn’t surprise me at all,” Moyer said. “I think we’re just seeing the tip of the iceberg, I’m afraid.”

Hispanic, nonwhite populations continue to grow

Colorado is growing more diverse, though it lags the nation as a whole. 

The Census Bureau calculated a diversity index based on the probability that two people meeting randomly would be from different race or ethic groups. Nationwide, that probability was 61% in 2020, up from about 55% in 2010.

Colorado’s diversity index is 52%, up from almost 47% a decade ago. Arapahoe and Denver counties lead the state in the diversity index at 62%, followed by Adams County at 61% and Crowley County at 58%. Another 13 counties exceed the statewide index.

Among the state’s most diverse cities, with populations of 50,000 or more, were:

  • Commerce City, at nearly 49% Hispanic and 40% white population in 2020
  • Aurora, at 42% white,, 40% Hispanic, 15% Black and 6% Asian
  • Pueblo, at 49% Hispanic and 43% white
  • Thornton, at 51% white, 36% Hispanic and 6% Asian
  • Greeley, at 51% white and 40% Hispanic

People of Hispanic descent continue to be the largest minority group in Colorado, at more than 1.26 million people, or nearly 22% of the state population, according to the census data. That’s about 1 in 5 people, a slight increase from the 2019 population estimates. 

Some of the counties that saw significant growth also have significant and growing Latino communities, including Adams at 41.7% and Weld at 29.9%, according to the new numbers. 

That’s also where the preliminary draft map places the new 8th Congressional District, said Marco Dorado, Colorado state director for All on the Line, a group affiliated with the National Democratic Redistricting Committee.

The growing Latino population in that area is “something that can’t be overlooked, and it’s a consideration that both commissions need to dive deeper into understanding,” Dorado said. 

The new census data also showed a big increase — 276% — in the number of people nationwide who identify as mixed race compared with 2010. 

About 12.3% of Coloradans identified as two or more races, according to the 2020 data, a 310% change, or a difference of 535,214 people. 

Much of that increase, as well as other differences in ethnicity data, can be attributed to major changes to the way the Census Bureau asked people questions about their race and ethnicity, said Garner, the state demographer. 

Sandra Fish has covered government and politics in Iowa, Florida, New Mexico and Colorado. She was a full-time journalism instructor at the University of Colorado for eight years, and her work as appeared on CPR, KUNC, The Washington Post, Roll...

Shannon Najmabadi covered rural affairs and the rural economy for The Colorado Sun from 2021-2023.

Thy Vo previously was a politics reporter for The Colorado Sun.