Boulder County, Colorado

Boulder County is a place in the U.S. state of Colorado. It had a population of 330,758 people as of the 2020 census. The biggest city in Boulder County and also its main city is Boulder.

Boulder County is part of the Boulder, Colorado Metropolitan Statistical Area. This area is also included in a larger group of places called the Denver-Aurora-Greeley, CO Combined Statistical Area, which covers 12 counties.

History

Further information: Curse of the Boulder Valley

Boulder County was one of the original 17 counties created by the Territory of Colorado on November 1, 1861. It was named after Boulder City and Boulder Creek, which had many large rocks that made early gold mining difficult. The county’s borders have stayed almost the same since 1861, though a small part became the City and County of Broomfield in 2001.

Before European settlers arrived, the area was home to Native Americans led by Chief Niwot on the plains and Utes in the mountains. The first settlers were gold prospectors who arrived in 1858 and later founded the town of Boulder and Gold Hill in 1859, where they found plenty of gold.

In late December 2021, a big fire called the Marshall Fire burned near Boulder, Colorado. It was the most damaging fire in Colorado’s history, destroying many homes in the cities of Superior and Louisville, as well as some areas of Boulder County. Thousands of people had to leave their homes because of strong winds. The exact cause of the fire is still being investigated.

Geography

According to the U.S. Census Bureau, the county has a total area of 740 square miles (1,900 km²), of which 726 square miles (1,880 km²) is land and 14 square miles (36 km²) (1.9%) is water.

Adjacent counties

• Larimer County, Colorado – north
• Weld County, Colorado – east
• City and County of Broomfield, Colorado – southeast
• Jefferson County, Colorado – south
• Gilpin County, Colorado – south
• Grand County, Colorado – west

Major highways

• U.S. Highway 36 (Denver-Boulder Turnpike)
• U.S. Highway 287
• State Highway 7
• State Highway 42
• State Highway 52
• State Highway 66
• State Highway 72
• State Highway 93
• State Highway 119
• State Highway 170
• Northwest Parkway (tollway)

National protected areas

• Arapaho National Forest
• Roosevelt National Forest
• Indian Peaks Wilderness
• James Peak Wilderness

Rocky Mountain National Park is in Boulder County, Larimer County, and Grand County. Longs Peak, the park's highest summit at 4,345 meters (14,255 feet) elevation, is located in Boulder County.

State protected area

• Eldorado Canyon State Park

Scenic trails and byways

• Continental Divide National Scenic Trail
• Peak to Peak Scenic and Historic Byway

Historic district

• Colorado Chautauqua National Historic District

Demographics

2020 census

According to the 2020 census, Boulder County had a population of 330,758 people. About 18.8% of the residents were younger than 18 years old, and 15.5% were 65 years or older. The average age was 37.6 years. Most people, around 90.6%, lived in cities, while 9.4% lived in the countryside.

The racial makeup of the county was 77.4% White, 1.0% Black or African American, 0.8% American Indian and Alaska Native, 5.0% Asian, and smaller groups of other races. About 14.6% of the population were Hispanic or Latino of any race.

There were 132,551 homes in the county. About 26.4% of these homes had children under 18 living in them. Many homes, around 28.7%, were lived in by just one person.

There were 140,848 places to live, but 5.9% of them were empty. Of the homes that were used, 61.0% were owned by the people living there, and 39.0% were rented.

2000 census

The 2000 census counted 271,651 people in Boulder County. The racial makeup was 88.54% White, with smaller groups of other races. About 10.46% of the population were Hispanic or Latino of any race.

There were 114,680 homes, and 30.70% of them had children under 18. About 48.90% were families living together, while 40.00% were not families. The average family size was 3.03 people.

Income and rankings

In 2014, the middle income for a home in the county was $69,407, and for a family it was $94,938. Men earned about $65,489 on average, while women earned about $48,140. About 7.0% of families and 14.6% of all people lived below the poverty line, including some younger people and older adults.

In 2017, Boulder County was named the best place for smart and educated people to live in the United States by Bloomberg.

Government

Boulder County is divided into three areas, and each area has a commissioner who is elected by everyone in the county. These three commissioners make up the Board of Commissioners, and they speak for the whole county. Each commissioner must live in their own area and can be elected for up to two four-year terms.

The Board of Commissioners works full time and decides the budget for the whole county government. They also watch over ten county departments and the daily work of the county. Boulder County also has seven other important officials elected by everyone in the county, such as the District Attorney for the 20th Judicial District.

Politics

Boulder County used to support Republican candidates in presidential elections from 1920 to 1984, except during big Democratic years in 1932, 1936, and 1964. But since the late 1980s, the county has strongly supported Democratic candidates. Since 1988, it has consistently voted for Democrats and is now one of the most liberal areas in Colorado.

In recent years, support for Republican candidates has dropped a lot. In the elections from 2008 to 2024, Republican candidates received less than 28% of the vote in Boulder County. In 2020, Democrat Joe Biden won over 77% of the vote, the best result for a Democrat since 1896. In 2024, Kamala Harris got 76.5% of the vote, which was also a very strong showing for a Democrat.

Boulder County has also shown its progressive views in other votes. For example, in 2006, most voters in the county opposed a state amendment about marriage, even though it passed statewide. In 2012, over 66% of the county voted to legalize marijuana in Colorado.

Local courts

The 20th Judicial District of Colorado serves Boulder County. It includes eight judges who handle many types of cases. There is also a Boulder County Court with five judges and six magistrates who handle smaller cases.

Boulder County has two main courthouses. The Boulder County Justice Center in Boulder is the main office for the 20th Judicial District and includes the office of the district attorney. The Longmont Courthouse in Longmont supports the County Court and the District Attorney's Office.

Communities

Boulder County has many places where people live. Some of these places are called cities, and others are called towns or census-designated places. There are also some smaller areas that are not officially named towns or cities.

Cities

• Boulder
• Lafayette
• Longmont (partly in Weld County)
• Louisville

Towns

• Erie (partly in Weld County)
• Jamestown
• Lyons
• Nederland
• Superior (partly in Jefferson County)
• Ward

Census-designated places

• Allenspark
• Altona
• Bark Ranch
• Bonanza Mountain Estates
• Coal Creek (partly in Gilpin County and Jefferson County)
• Crisman
• Eldora
• Eldorado Springs
• Glendale
• Gold Hill
• Gunbarrel
• Hidden Lake
• Lazy Acres
• Leyner
• Mountain Meadows
• Niwot
• Paragon Estates
• Pine Brook Hill
• Seven Hills
• St. Ann Highlands
• Sugarloaf
• Sunshine
• Tall Timber
• Valmont

Other unincorporated communities

• Caribou
• Canfield
• Gooding
• Hygiene
• Highland
• Liggett
• Morey
• Pinecliffe
• Pleasant View Ridge (partly in Weld County)
• Tabor

Education

Boulder County has several school districts that help educate students. Some of these include the Boulder Valley School District RE-2, Estes Park School District R-3, St. Vrain Valley School District RE-1J, and Thompson School District R-2J. These districts work together to provide schools and learning opportunities for children living in the area.