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Jefferson County, Colorado facts for kids

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Jefferson County
Jefferson County Courthouse in Golden, nicknamed "Colorado's Taj Mahal" for its dome architecture
Jefferson County Courthouse in Golden, nicknamed "Colorado's Taj Mahal" for its dome architecture
Flag of Jefferson County
Flag
Official seal of Jefferson County
Seal
Motto(s): 
Gateway to the Rocky Mountains
Map of Colorado highlighting Jefferson County
Location within the U.S. state of Colorado
Map of the United States highlighting Colorado
Colorado's location within the U.S.
Country  United States
State  Colorado
Founded November 1, 1861
Named for Jefferson Territory
Seat Golden
Largest city Lakewood
Area
 • Total 774 sq mi (2,000 km2)
 • Land 764 sq mi (1,980 km2)
 • Water 9.8 sq mi (25 km2)  1.3%
Population
 (2020)
 • Total 582,910
 • Density 763/sq mi (295/km2)
Time zone UTC−7 (Mountain)
 • Summer (DST) UTC−6 (MDT)
Congressional districts 1st, 2nd, 6th, 7th

Jefferson County is a county located in the U.S. state of Colorado. As of the 2020 census, the population was 582,910, making it the fourth-most populous county in Colorado. The county seat is Golden, and the most populous city's Lakewood.

Jefferson County is included in the Denver-Aurora-Lakewood, CO Metropolitan Statistical Area. Located along the Front Range of the Rocky Mountains, Jefferson County is adjacent to the state capital of Denver.

In 2010, the center of population of Colorado was located in Jefferson County.

The county's slogan is the "Gateway to the Rocky Mountains", and it is commonly nicknamed Jeffco. The name Jeffco is incorporated in the name of the Jeffco School District, the Jeffco Business Center Metropolitan District No. 1, and several businesses located in Jefferson County. Jeffco is also incorporated in the unofficial monikers of many Jefferson County agencies. The Rocky Mountain Metropolitan Airport operated by Jefferson County was previously known as the Jeffco Airport.

A major employer in Jefferson County is the large Coors Brewing Company in Golden. Also, the state-supported Colorado School of Mines, a university specializing in mining, geology, chemistry, and engineering is located in Jefferson County.

History

On August 25, 1855, the Kansas Territorial Legislature created Arapahoe County to govern the entire western portion of the territory. The county was named for the Arapaho Nation of Native Americans who lived in the region.

In June 1858, gold was discovered along the South Platte River in Arapahoe County (in present-day Englewood) by William Greeneberry Russell and Sam Bates who had been following up the June 22, 1850, discovery of gold on Ralston Creek in today's Jefferson County by Lewis Ralston, for whom the creek was named. This discovery precipitated the Pike's Peak Gold Rush. The Doniphan Party upon arriving upon Clear Creek discovered markers left over from earlier mining in 1834 by the Estes Party, placed their own alongside and on November 29, 1858, founded the future county's first town of Arapahoe City upon the land southeast of today's West 44th Avenue and McIntyre Street (with West 44th running through the town). On June 16, 1859, its second town, Golden, Colorado, was founded in the valley to the west. Many residents of the mining region felt disconnected from the remote territorial governments of Kansas and Nebraska, so they voted to form their own Territory of Jefferson on October 24, 1859. The following month on November 28, 1859, the Jefferson Territorial Legislature organized 12 counties for the new territory, including Jefferson County. Jefferson County was named for the namesake of the Jefferson Territory, Thomas Jefferson, the principal author of the Declaration of Independence and the nation's third president. Golden City was elected on January 2, 1860, as the county seat of Jefferson County. Robert Williamson Steele, Governor of the Provisional Government of the Territory of Jefferson from 1859 to 1861, built his home in the county at Mount Vernon and later at Apex. Originally Jefferson County's borders extended to the 40th parallel north, the South Platte River (excluding the town of Highland) to the east, and to Bear Creek to the south.

The Jefferson Territory never received federal sanction, but during his last week in office, President James Buchanan signed an act which organized the Territory of Colorado on February 28, 1861. That November 1, the new Colorado General Assembly organized the 17 original counties of Colorado, including Jefferson County. The reorganized Jefferson County extended to most of its current borders and Golden continued as county seat. In 1908, the southern tip of Jefferson County was transferred to Park County, reducing Jefferson County to its present length of 54 miles (87 km). Several annexations by the City & County of Denver and the 2001 consolidation of the City & County of Broomfield removed the east and extreme northeastern corner of the county, respectively.

Geography

Long Scraggy Peak
Long Scraggy Peak in the southeastern part of the county.

According to the U.S. Census Bureau, the county has a total area of 774 square miles (2,000 km2), of which 764 square miles (1,980 km2) is land and 9.8 square miles (25 km2) (1.3%) is water.

Adjacent counties

Jefferson County is one of the few counties in the United States to border as many as ten counties.

Major highways

  • I-70 (CO).svg Interstate 70
  • I-70 Bus.
  • US 6.svg U.S. Highway 6
  • US 40.svg U.S. Highway 40
  • US 285.svg U.S. Highway 285
  • Colorado 8.svg State Highway 8
  • Colorado 58.svg State Highway 58
  • Colorado 72.svg State Highway 72
  • Colorado 74.svg State Highway 74
  • Colorado 75.svg State Highway 75
  • Colorado 93.svg State Highway 93
  • Colorado 121.svg State Highway 121
  • Colorado 391.svg State Highway 391
  • Colorado 470.svg State Highway 470
  • Chatfield Ave
  • 44th Ave

Recreational areas

  • Alderfer/Three Sisters Park
  • Apex Park
  • Bear Creek Lake Park
  • Centennial Cone Park
  • Clear Creek Canyon Park
  • Coal Creek Canyon
  • Crown Hill Park
  • Deer Creek Canyon Park
  • Elk Meadow Park
  • Evergreen Lake
  • Fairmount Trail
  • Flying J Ranch Park
  • Hildebrand Ranch Park
  • Hiwan Homestead Museum
  • Lair o' the Bear Park
  • Lewis Meadows Park
  • Lookout Mountain Nature Center
  • Matthews/Winters Park
  • Meyer Ranch Park
  • Mount Falcon Park
  • Mount Galbraith Park
  • Mount Glennon
  • Mount Lindo
  • North Table Mountain Park
  • Pine Valley Ranch Park
  • Ranson/Edwards Homestead Ranch
  • Reynolds Park
  • Sister City Park
  • South Table Mountain Park
  • South Valley Park
  • Standley Lake Regional Park
  • Van Bibber Park
  • Welchester Tree Grant Park
  • White Ranch Park
  • Windy Saddle Park
  • Urban Trails

Demographics

Historical population
Census Pop.
1870 2,390
1880 6,804 184.7%
1890 8,450 24.2%
1900 9,306 10.1%
1910 14,231 52.9%
1920 14,400 1.2%
1930 21,810 51.5%
1940 30,725 40.9%
1950 55,687 81.2%
1960 127,520 129.0%
1970 233,031 82.7%
1980 371,753 59.5%
1990 438,430 17.9%
2000 527,056 20.2%
2010 534,543 1.4%
2020 582,910 9.0%
2023 (est.) 576,366 7.8%
U.S. Decennial Census

1790-1960 1900-1990

1990-2000 2010-2020

As of the census of 2000, there were 527,056 people, 206,067 households, and 140,537 families residing in the county. The population density was 683 people per square mile (264 people/km2). There were 212,488 housing units at an average density of 275 people per square mile (106 people/km2). The racial makeup of the county was

90.59%
White
0.89%
Black or African American
0.75%
Native American
2.28%
Asian
0.08%
Pacific Islander
3.23%
from other races
9.95% of the population were either Hispanic or Latino of any race
2.18% in two or more races

There were 206,067 households, out of which 33.40% had children under age 18 living with them, 55.10% were married couples living together, 9.10% had a female householder with no husband present, and 31.80% were non-families. 24.50% of all households were made up of individuals, of those 6.30% were someone living alone who was 65 years of age or older. The average household size was 2.52, and the average family size was 3.03 persons.

In the county, the population ages were spread out:

25.30%
under age 18
8.10%
aged 18–24
32.10%
aged 25–44
24.90%
aged 45–64
9.60%
65 years of age or older
The median age was 37 years.

For every 100 females there were 99.00 males. For every 100 females age 18 and over, there were 96.80 males.

The median income for a household in the county was $57,339, and the median income for a family was $67,310. Males had a median income of $45,306 versus $32,372 for females. The per capita income for the county was $28,066. About 3.40% of families and 5.20% of the population were below the poverty line, including 5.80% of those under age 18, and 5.10% of those age 65 or over.

According to a report in the JAMA, residents of Jefferson County had a 2014 life expectancy of 80.02 years.

Education

The sole school district serving the county is Jefferson County School District R-1.

Private schools
  • Colorado Academy
Higher Education
  • Colorado Christian University
  • Colorado School of Mines
  • Red Rocks Community College
  • Rocky Mountain College of Art and Design

Jefferson County Public Library is the county library system.

Recreation

State parks

National forests and wilderness

National wildlife refuges

Historic trail

  • South Platte Trail

Recreational trails

  • American Discovery Trail
  • Apex National Recreation Trail
  • Big Dry Creek National Recreation Trail
  • Colorado Trail
  • Platte River Greenway National Recreation Trail
  • Two Ponds National Recreation Trail

Scenic byway

  • Lariat Loop Scenic and Historic Byway

Golf course

  • Hiwan Golf Club
  • Indian Tree Golf Club

Communities

Cities

Towns

Census-designated places

Unincorporated communities

See also

Kids robot.svg In Spanish: Condado de Jefferson (Colorado) para niños

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