Once an agricultural and mining area, Jefferson County, Colorado now is a thriving suburban, business, industrial and residential community.
It's a place where the great plains meet the Rocky Mountains with some of the most magnificent scenery in the country. We have rolling grasslands and craggy rock formations, natural foothills, rugged mountains and tumbling mountain streams.
Jefferson County is a place 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.
General boundaries for the county 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. Maps >>
Plenty of both mom and pop shops and Fortune 500 companies are headquartered here. Get more information about business or opportunities.
Jefferson County is the fourth largest county in Colorado with a population estimated at 538,323, according to the State Demographer's Office as of July 2007 - view POPULATION ESTIMATES FOR COUNTIES, 2000 - 2007 (Ranked By 2007 Population) in PDF format.
Jeffco citizens make their homes on mountain tops as well as in suburban communities.
Cities and Towns
Many cities or towns are located wholly or partially in Jefferson County - Arvada, Bow Mar, Edgewater, Golden, Lakeside, Lakewood, Littleton, Morrison, Mountain View, Superior, Westminster and Wheat Ridge.
The unincorporated portions 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, South Jeffco and Pine.
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.
Situated at the heart of the government campus is the 531,000 square foot building.
- Key to its intrigue is the 125-foot glass-enclosed dome atrium stylized both after ancient Greek architecture and the rotunda designed by Thomas Jefferson for the University of Virginia.
- Large brass colored spheres decorate the exterior near the top of the building.
- The building's 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 both the county's administrative offices on one side and courts on the other.
- Spectacular views of the Rocky Mountain foothills are provided on each of the facility's five floors.
The Great Outdoors
Outdoor lovers have three national forests and two state parks to choose from.
Located partly in Jefferson County are Pike, Roosevelt and Arapahoe national forests, and Golden Gate Canyon State Park and the Chatfield State Recreation Area.
The nationally recognized Open Space program in Jefferson County offers a variety of outdoor activities.
Jefferson County Library
The Jefferson County Public Library (JCPL) shares a diverse collection of more than 1.2 million items among its 10 libraries. It also provides proactive outreach to Jeffco citizens via a Bookmobile, a Traveling Children's Library and the eTrain, a mobile computer training lab. The Library offers a vast array of materials, including books, periodicals, CDs, DVDs, audio books and ebooks. In addition, it offers more than 6,000 classes a year, covering a wide range of topics -- from early literacy for babies and toddlers, to homework help for children, to computer and Internet training for adults, to tax preparation assistance for Seniors and more. It also has meeting rooms available for use by community groups. Explore the Library's Web site at www.jeffcolibrary.org to find the latest Library news, reserve items and look into our class offerings. Our Web site also contains more than 80 high-quality subscription databases offering everything from newspapers and magazines to job search assistance to medical information--all free with your library card. Main phone number: 303-235-5275.
Jefferson County has a first-class public school system. Public school children attend schools in the Jefferson County R-1 School District. Residents have access to at least a dozen institutions of higher education. Get more information about educational resources.
Latest Population Figures: Countywide: 538,323, Unincorporated: 187,936
Latitude and Longitude: The latitude and longitude of the Jefferson County Administration and Courts Facility is 105 11' 56'' W, 39 43' 38'' N. The latitude and longitude of any other address within Jefferson County is available by visiting our Address Wizard.
- Land Area: 774 square miles - 497,280 acres
- Incorporated area: 116.5 square miles
- Unincorporated area: 655 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%
Climate: Average days of sunshine: 255 per year
- Coldest month: January
- Average temp: 30 degrees
- Hottest month: July
- Average temp: 74 degrees
- Annual precipitation: 15.4 inches
- Average annual snowfall: 60.3 inches
- Average humidity: 40 percent
Things To Do in Jeffco
Brief History of Jefferson County
A Chronology of the History of Jefferson County
Historical Census Data
Archives and Records Web Site
Last Modified: Jan 19, 2011 09:35 AM