Jefferson County, Colorado

Jefferson County is a county located in the U.S. state of Colorado. As of the 2020 census, the population was 582,910,[1] making it the fourth-most populous county in Colorado. The county seat is Golden,[2] and the most populous city's Lakewood.

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
Official seal of Jefferson County
Motto: 
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.
Coordinates: 39°35′N 105°15′W / 39.59°N 105.25°W / 39.59; -105.25
Country United States
State Colorado
FoundedNovember 1, 1861
Named forJefferson Territory
SeatGolden
Largest cityLakewood
Area
 • Total774 sq mi (2,000 km2)
 • Land764 sq mi (1,980 km2)
 • Water9.8 sq mi (25 km2)  1.3%
Population
 (2020)
 • Total582,910
 • Density763/sq mi (295/km2)
Time zoneUTC−7 (Mountain)
 • Summer (DST)UTC−6 (MDT)
Congressional districts1st, 2nd, 6th, 7th
Websitewww.jeffco.us

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.[3]

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 edit

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).[4] 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.[5] 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.[6] 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 edit

 
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.[7]

Adjacent counties edit

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

Major highways edit

Recreational areas edit

  • 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 edit

Historical population
CensusPop.Note
18702,390
18806,804184.7%
18908,45024.2%
19009,30610.1%
191014,23152.9%
192014,4001.2%
193021,81051.5%
194030,72540.9%
195055,68781.2%
1960127,520129.0%
1970233,03182.7%
1980371,75359.5%
1990438,43017.9%
2000527,05620.2%
2010534,5431.4%
2020582,9109.0%
U.S. Decennial Census[8]

1790-1960[9] 1900-1990[10]

1990-2000[11] 2010-2020[1]

As of the census[12] 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.[13]

Education edit

The sole school district serving the county is Jefferson County School District R-1.[14]

Private schools
Higher Education


Jefferson County Public Library is the county library system.

Government and infrastructure edit

Government edit

The Board of County Commissioners operates as the governing body of the county. Established in 1861, the board consists of three commissioners who are elected at-large to four-year terms. The board sets policies that guide county programs and operations which serves residents and businesses. There are several elected officials that oversee a department or aspect of county operations.[16]

Board of County Commissioners[16][17]
District Commissioner Party
District 1 Tracy Kraft-Tharp Democratic
District 2 Andy Kerr Democratic
District 3 Lesley Dahlkemper Democratic
Elected County Officials[16][17]
Title Official Party
Assessor Scot Kersgaard Democratic
Clerk and Recorder Amanda Gonzalez Democratic
Coroner Dr. Annette Cannon Democratic
District Attorney Alexis King Democratic
Sheriff Regina "Reggie" Marinelli Democratic
Surveyor Robert Hennessy Republican[18]
Treasurer Gerald "Jerry" DiTullio Democratic

Sheriff's office edit

The Jefferson County Sheriff is an oldest elective office in Jefferson County (along with Clerk and Recorder, Assessor and Treasurer) and among the very first popularly elected offices in Colorado, established in 1859 with the first Sheriff, Walter Pollard, elected on January 2, 1860.[19] Its office holders over the course of over 150 years have included some of the most noted law enforcement officers in Colorado history.

The Jefferson County Sheriff's Office responded to the 1999 Columbine High School massacre, and investigated it together with the F.B.I. The Sheriff's Office received backlash after it was revealed the agency had the perpetrators Eric Harris and Dylan Klebold in and out of custody prior to the shooting. After the shooting Sue Klebold sued the Sheriff's office for failing to prevent their son from carrying out the Columbine High shootings. According to a "notice of intent to sue" filed by Susan and Thomas Klebold, county officials were "reckless, willful and wanton" in the way they handled a 1998 police report about Eric Harris' Internet ravings.[20][21][22] This lawsuit was dismissed along with several others pertaining to the shooting.[23]

The current county sheriff is Regina "Reggie" Marinelli.[24] She was in elected 2022 and became the first woman to do so in county history and became the first Democrat to hold the office in nearly a century. She previously worked in the county Sheriff's Office for over 30 years.[25]

Politics edit

Jefferson County was a Republican stronghold for most of the 20th century. However, it has voted Democratic in every presidential election since 2008, consistent with the general trend in the Denver metropolitan area. In 2020, Joe Biden won the largest percentage for a Democratic presidential candidate since 1916.

United States presidential election results for Jefferson County, Colorado[26]
Year Republican Democratic Third party
No.  % No.  % No.  %
2020 148,417 39.33% 218,396 57.88% 10,545 2.79%
2016 138,177 42.01% 160,776 48.89% 29,930 9.10%
2012 144,197 46.36% 159,296 51.21% 7,559 2.43%
2008 131,628 44.61% 158,158 53.60% 5,282 1.79%
2004 140,644 51.79% 126,558 46.60% 4,366 1.61%
2000 120,138 51.02% 100,970 42.88% 14,383 6.11%
1996 101,517 48.41% 89,494 42.67% 18,712 8.92%
1992 82,705 37.05% 80,834 36.22% 59,664 26.73%
1988 110,820 56.39% 81,824 41.64% 3,867 1.97%
1984 124,496 68.92% 53,700 29.73% 2,432 1.35%
1980 97,008 59.66% 41,525 25.54% 24,078 14.81%
1976 87,080 60.44% 52,782 36.64% 4,211 2.92%
1972 80,082 69.88% 31,555 27.54% 2,960 2.58%
1968 50,847 56.90% 31,392 35.13% 7,118 7.97%
1964 33,398 43.48% 43,162 56.19% 252 0.33%
1960 34,105 59.62% 22,962 40.14% 137 0.24%
1956 25,398 63.71% 14,270 35.80% 197 0.49%
1952 19,971 63.05% 11,509 36.34% 194 0.61%
1948 9,903 51.29% 9,145 47.36% 260 1.35%
1944 9,815 57.20% 7,277 42.41% 68 0.40%
1940 8,780 52.81% 7,745 46.59% 100 0.60%
1936 5,271 41.10% 7,283 56.79% 271 2.11%
1932 5,522 45.83% 6,023 49.99% 503 4.17%
1928 6,754 69.09% 2,880 29.46% 141 1.44%
1924 4,869 63.69% 1,271 16.63% 1,505 19.69%
1920 3,593 61.52% 1,941 33.24% 306 5.24%
1916 2,040 36.60% 3,368 60.42% 166 2.98%
1912 1,011 18.87% 2,309 43.10% 2,037 38.03%
1908 2,623 48.58% 2,583 47.84% 193 3.57%
1904 2,903 60.76% 1,739 36.40% 136 2.85%
1900 1,807 44.79% 2,138 53.00% 89 2.21%
1896 300 8.41% 3,176 88.99% 93 2.61%
1892 792 42.86% 0 0.00% 1,056 57.14%
1888 970 52.92% 767 41.84% 96 5.24%
1884 845 50.97% 743 44.81% 70 4.22%
1880 832 49.55% 790 47.05% 57 3.39%

Recreation edit

State parks edit

National forests and wilderness edit

National wildlife refuges edit

Historic trail edit

Recreational trails edit

Scenic byway edit

Golf course edit

Communities edit

Cities edit

Towns edit

Census-designated places edit

Unincorporated communities edit

See also edit

References edit

  1. ^ a b "State & County QuickFacts". United States Census Bureau. Retrieved September 5, 2021.
  2. ^ "Find a County". National Association of Counties. Archived from the original on May 31, 2011. Retrieved June 7, 2011.
  3. ^ "Centers of Population by State: 2010". United States Census Bureau. Archived from the original on January 3, 2014. Retrieved June 8, 2014.
  4. ^ "Historically Jeffco 2011". Jefferson County Historical Commission. 2011. Retrieved February 25, 2024.
  5. ^ Gannett, Henry (1905). The Origin of Certain Place Names in the United States. Govt. Print. Off. pp. 168.
  6. ^ "An Act to provide a temporary Government for the Territory of Colorado" (PDF). Thirty-sixth United States Congress. February 28, 1861. Archived (PDF) from the original on October 25, 2004. Retrieved November 26, 2007.
  7. ^ "US Gazetteer files: 2010, 2000, and 1990". United States Census Bureau. February 12, 2011. Retrieved April 23, 2011.
  8. ^ U.S. Decennial Census (Report). United States Census Bureau. Retrieved June 8, 2014.
  9. ^ Historical Census Browser. UVA Libraries (Report). University of Virginia. Retrieved June 8, 2014.
  10. ^ Population of Counties by Decennial Census: 1900 to 1990 (Report). United States Census Bureau. Retrieved June 8, 2014.
  11. ^ Ranking Tables for Counties: 1990 and 2000 (PDF) (Report). Census 2000. United States Census Bureau. PHC-T-4. Archived (PDF) from the original on March 27, 2010. Retrieved June 8, 2014.
  12. ^ "U.S. Census" (main website). United States Census Bureau. Retrieved May 14, 2011.
  13. ^ Dwyer-Lindgren, Laura (May 8, 2017). "Inequalities in life expectancy among U.S. counties, 1980 to 2014". JAMA Internal Medicine. 177 (7): 1003–1011. doi:10.1001/jamainternmed.2017.0918. PMC 5543324. PMID 28492829.
  14. ^ "2020 CENSUS - SCHOOL DISTRICT REFERENCE MAP: Jefferson County, CO" (PDF). U.S. Census Bureau. Archived (PDF) from the original on July 20, 2022. Retrieved July 19, 2022.Text list
  15. ^ "FCI Englewood Contact Information Archived February 21, 2013, at the Wayback Machine." Federal Bureau of Prisons. Retrieved on July 28, 2010.
  16. ^ a b c "Leadership | Jefferson County, CO". www.jeffco.us. Retrieved November 1, 2023.
  17. ^ a b "Jefferson County Elected Officials". Jefferson County Democratic Party. Retrieved November 1, 2023.
  18. ^ "Republican Party Officials - Jefferson County Republican Party". Jefferson County Republicans. Retrieved November 1, 2023.
  19. ^ "The Western Mountaineer". January 11, 1860 – via www.coloradohistoricnewspapers.org.
  20. ^ "Klebold family plans to sue Jeffco".
  21. ^ "Judge dismisses all but one Columbine lawsuit". CNN. November 27, 2001. Retrieved May 9, 2022.
  22. ^ "Parents sue JeffCo". Retrieved May 9, 2017.
  23. ^ "Judge dismisses all but one Columbine lawsuit". CNN. November 27, 2001. Retrieved December 19, 2021.
  24. ^ "Jefferson County Sheriff Regina Marinelli officially steps into new role - CBS Colorado". www.cbsnews.com. January 10, 2023. Retrieved November 1, 2023.
  25. ^ Leary, Jaime (November 15, 2022). "Jefferson County Sheriff-elect Regina Marinelli is first woman to lead the agency, and first Democrat in almost a century". CBS Colorado. Retrieved November 1, 2023.
  26. ^ Leip, David. "Dave Leip's Atlas of U.S. Presidential Elections". uselectionatlas.org. Retrieved November 26, 2020.

External links edit

39°35′N 105°15′W / 39.59°N 105.25°W / 39.59; -105.25