Life in Jeffco

Life in Jefferson County

Once an agricultural and mining area, Jefferson County, Colorado is a thriving suburban, business, industrial, recreational and residential community. The county, formally organized in 1861 by the Colorado Territorial Legislature, takes the name of Thomas Jefferson, the third president of the United States.

Jefferson County is a place where the great plains meet the Rocky Mountains with some of the most magnificent scenery in the country. It features rolling grasslands and craggy rock formations, natural foothills, rugged mountains and tumbling mountain streams.

The LandscapeImage of mountain range from trail with trees and blue skies

Jefferson County is filled with magnificent wonders only nature can provide. Not ignoring its agricultural and mining roots, Jefferson County has worked to create a delicate balance between that past while supporting a thriving business community and providing for safe neighborhoods.

The county's general boundaries include West 120th Avenue in Westminster on the north, Sheridan Boulevard on the east and Pike National Forest to the south. The county extends west into the mountains to meet Gilpin, Clear Creek and Park counties. View maps of Jefferson.

The Great Outdoors

Outdoor lovers have many Jefferson County Open Space Parks, three national forests and two state parks from which to choose.

Pike, Roosevelt and Arapahoe national forests, Golden Gate Canyon State Park and Chatfield State Recreation Area are all partially located in Jefferson County.

The county's nationally recognized Open Space program offers a variety of outdoor activities. See the Jeffco Open Space website for information about the many activities and amenities our Jefferson County Parks have to offer.


A plentiful mix of mom-and-pop shops and Fortune 500 companies are headquartered here. See our Business page to get more information about business opportunities.


Jefferson County is the fourth-largest county in Colorado. Its citizens make their homes on mountain tops as well as in suburban communities. The latest data was primarily derived from 2010 US Census, considered the baseline demographic data for population and housing estimates until the next decennial census occurs in 2020. For all of the information, see the Demographics page within the Planning and Zoning website.

Cities & Towns

Many cities or towns are located wholly or partially in Jefferson County

The unincorporated areas of the county are home to many communities including, but not limited to:

  • Applewood
  • Aspen Park
  • Bergen Park
  • Buffalo Creek
  • Conifer
  • Evergreen 
  • Genesee
  • Idledale
  • Indian Hills 
  • Kittredge
  • Pine
  • South Jeffco

County Headquarters County headquarters aerial image of multi story building with large fan like parking lot

The magnificent, six-level Jefferson County Administration and Courts Facility, located at the intersection of 6th Avenue and Jefferson County Parkway in Golden, can be seen for miles from nearly all directions.

The 531,000-square foot building is situated at the heart of the government campus.

  • Key to its intrigue is the 125-foot, glass-enclosed dome atrium, stylized after ancient Greek architecture and the rotunda Thomas Jefferson designed for the University of Virginia
  • Large, brass-colored spheres decorate the exterior near the top of the building
  • Its wheat and adobe coloring blends nicely with rock, buffalo grass and iron-rich, red earth indigenous to the area
  • The dome is centered between two, five-story wings, housing the county's administrative offices on one side and courts on the other
  • Spectacular views of the Rocky Mountain foothills can be seen from each of the facility's five floors

Library System

The Jefferson County Public Library (JCPL) shares a diverse collection of more than 1.2 million items among its 10 libraries. It provides proactive outreach to Jeffco citizens with a Bookmobile, Traveling Children's Library and the eTrain mobile computer- training lab.

The Library offers a vast array of materials, including books, periodicals, CDs, DVDs, audio books and ebooks. It offers more than 6,000 classes each year, covering a wide range of topics - from early literacy for babies and toddlers, homework help for children, computer and Internet training for adults, to tax preparation assistance for seniors and more. The Library also has meeting rooms available for community groups to use.

See our Library page to connect to the section of the Jefferson County Public Library site to find the latest library news, class offerings and to reserve items. The website also contains more than 80, high-quality subscription databases offering everything from newspapers and magazines to job search assistance and medical information - all free with your library card.


The county has a first-class public school system, Jefferson County R-1 School District. Residents have access to at least a dozen institutions of higher education. See our Education page to get more information about educational resources.

County Statistics

Latest Population Figures 

(as of July 1, 2010)

  • Countywide: 535,734
  • Unincorporated: 188,368

Latitude & Longitude

The latitude and longitude for address within Jefferson County are available by visiting our Address Wizard application.

  • Land Area: 773 square miles - 494,535 acres
  • Incorporated area: 122 square miles
  • Unincorporated area: 651 square miles
  • Mountain area: 557 square miles, 72%
  • Plains area: 217 square miles, 28%
  • Pike National Forest: 172 square miles 22%
  • Roosevelt and Arapahoe National Forests: 4 square miles, 0.5%


  • Average days of sunshine: 255 per year
  • Average temperature: 30 degrees
  • Average temp: 74 degrees
  • Annual precipitation: 15.4 inches
  • Average annual snowfall: 60.3 inches
  • Average humidity: 40%
  • Coldest month: January
  • Hottest month: July