History & Demographics

Boulder County is home to moer than 300,000 residents and includes some of the most diverse, natural landscapes and sustainable development along the Front Range. The county seat resides in the City of Boulder.

Boulder County Government

From visionary open space, land use and sustainability policies to forward-thinking public services programs, our county government helps foster a vibrant, healthy and active community.

Environmental Sustainability

Boulder County is a national leader in innovative sustainability efforts. The county’s EnergySmart service was honored with a national Innovation in Government Award. The Zero Waste program advocates for eliminating waste by modeling resource management on the waste-free and self-sustaining systems found in nature.

Open Space Conservation

The county has shown a dedication to preserving and maintaining its open space. Protecting open lands remains a core value of the government today. By providing activities, events and services that engage the community in open space conservation and recreation, Boulder County helps to ensure that critical wildlife habitats, farms and areas for recreation will be around for generations to come.

Supportive Community Programs

Programs such as the Circles Campaign, the Area Agency on Aging, the Community Action Program, Workforce Boulder County and the Boulder County Housing Authority provide residents with the tools and support they need. Boulder County works on important issues including food safety, medical and mental health services, wellness and nutrition, financial and transportation assistance, disease prevention, substance abuse and addiction, and aging services.

Transportation Services

Boulder County’s transportation programs are designed to increase mobility and reduce congestion throughout Boulder County. Providing a reliable network of roadways, bikeways, trails and transit service to the citizens of Boulder County while ensuring the health, safety and welfare of the public is our goal. Boulder County coordinates, provides and maintains a high quality, safe and multi-modal transportation networks and related services, in a responsive manner, within budget, on schedule and resulting in high customer satisfaction.

Academia & Scientific Research in Boulder County


  • University of Colorado at Boulder
  • Naropa University 
  • Front Range Community College
  • Boulder Valley School District
  • St. Vrain Valley School District

Scientific Facilities

  • National Center for Atmospheric Research (NCAR)
  • National Institute of Standards and Technology (NIST)
  • National Oceanic and Atmospheric Administration (NOAA)
  • National Ecological Observatory Network (NEON)


Boulder County’s landscape features everything from farmland and rolling grasslands in the plains to the high peaks of the Continental Divide.

Located in north-central Colorado, northwest of Denver, the county’s landscape includes several dense urban centers surrounded by rural buffer zones and mountain communities, plus portions of Rocky Mountain National Park.

  • 741 square miles
  • Eastern slope of the Rocky Mountains
  • Elevation: Ranges from approximately 5,000 to 14,000 feet


As of 2013, Boulder County’s population was estimated to be 310,048 according to the U.S. Census Bureau:

Population Graphic

*Includes towns of Erie, Jamestown, Lyons, Nederland, Superior and Ward, and unincorporated areas such as the communities of Allenspark, Eldorado Springs, Gunbarrel and Niwot.

History – County & Courthouse

  • 1803: Thanks to the Louisiana Purchase, territory within what is now Boulder County becomes part of the United States
  • 1858: Gold was discovered in Dry Creek, stimulating the Pikes Peak Gold Rush
  • 1859: Coal was discovered in the Marshall area southeast of Boulder; The first record of modern settlement in Boulder County
  • 1861: The Colorado Territory was created
    • Boulder one of 17 counties represented in the first Territorial Assembly
    • Native Americans were the first inhabitants of the county
    • Followed by settlers, gold miners, farmers, coal miners and traders
  • 1866: Boulder County’s first newspaper, the Valmont Bulletin, began publication (later renamed the Boulder Valley News)
  • 1869: The first Boulder County Fair took place; The Boulder County Agricultural Society was founded
  • 1873: The first railroad was extended to Boulder County
  • 1882: Cornerstone of the original Boulder County Courthouse was laid
    • Building marked the official designation of a public square
    • Meeting place of the Boulder County Commissioners
    • Original structure was considered elaborate for a small pioneer town
  • 1890: The Boulder Daily Camera was founded
  • 1894: The Great Boulder Flood
  • 1898: The Chautauqua Auditorium was opened on July 4th
  • 1910: The Boulder County coal miners’ strike 
  • 1932: The original courthouse and many records were destroyed by fire
  • 1934: New courthouse built on the same site
  • 1962: Two wings were added to the courthouse complex
  • 1970: The Boulder County Comprehensive Plan was adopted
  • 1973: Boulder County’s first open space land was purchased
  • 1976: Voters approved the Danish Plan, a 2% growth limitation referendum
  • 1986: The Lafayette-Louisville Downtown Revitalization Partnership was established
  • 1993: The Boulder County Historic Preservation Ordinance was adopted


Administrative Services

Main: 303-441-3525
Fax: 303-441-4526


2025 14th St.
Map & Directions
Hours: 8 a.m.-4:30 p.m. M-F

Mailing Address

Administrative Services
PO Box 471
Boulder, CO 80306